Immersion exposure apparatus and device manufacturing method with liquid detection apparatus

ABSTRACT

An exposure apparatus for exposing a substrate by emitting exposure light thereto through a projection optical system and liquid, has a detection apparatus that detects whether the liquid is present on an object disposed lower than a front end of the projection optical system. Another detection apparatus has an emitting portion that emits detection light to an immersion area between the projection optical system and an object disposed on an image plane side thereof, and a light-receiving portion disposed at a predetermined position for the detection light; therein, at least one of size and shape of the immersion area is obtained based on light receiving results. The detection apparatus is used to detect the presence of liquid on such lower-disposed object, the state of the immersion area, or shape or contact angle of the liquid. Optimal measures are taken, based on detection results, for maintaining high exposure and measurement accuracies.

TECHNICAL FIELD

The present invention relates to an exposure apparatus that exposes asubstrate by irradiating the substrate with exposure light through aprojection optical system and a liquid, and to a device manufacturingmethod that uses that exposure apparatus.

BACKGROUND ART

Semiconductor devices and liquid crystal display devices are fabricatedby a so-called photolithography technique, wherein a pattern formed on amask is transferred onto a photosensitive substrate.

An exposure apparatus used in this photolithographic process has a maskstage that supports a mask, as well as a substrate stage that supports asubstrate, and transfers the pattern of the mask onto the substratethrough a projection optical system while successively moving the maskstage and the substrate stage.

There has been demand in recent years for higher resolution projectionoptical systems in order to handle the much higher levels of integrationof device patterns. The shorter the exposure wavelength used and thelarger the numerical aperture of the projection optical system, thehigher the resolution of the projection optical system. Consequently,the exposure wavelength used in exposure apparatuses has shortened yearby year, and the numerical aperture of projection optical systems hasincreased. Furthermore, the mainstream exposure wavelength currently isthe 248 nm KrF of excimer laser, but an even shorter wavelength 193 nmof ArF excimer laser is also being commercialized. In addition, as withresolution, the depth of focus (DOF) is important when performing anexposure. The following equations express the resolution R and the depthof focus δ, respectively.R=k ₁ ·λ/NA  (1)δ=±k ₂ ·λ/NA ²  (2)

Therein, λ is the exposure wavelength, NA is the numerical aperture ofthe projection optical system, and k₁ and k₂ are the processcoefficients. Equations (1) and (2) teach that if the exposurewavelength λ is shortened and the numerical aperture NA is increased inorder to enhance the resolution R, then the depth of focus δ decreases.

At this time, if the depth of focus δ becomes excessively small, then itwill become difficult to align the front surface of the substrate withthe image plane of the projection optical system, and there will be arisk of insufficient margin of focus during the exposure operation.

Accordingly, a liquid immersion method has been proposed, as disclosedin, for example, Patent Document 1 below, as a method to substantiallyshorten the exposure wavelength and increase the depth of focus. Thisliquid immersion method forms a liquid immersion area by filling a gapbetween the lower surface of the projection optical system and the frontsurface of the substrate with a liquid, such as water or an organicsolvent, thus taking advantage of the fact that the wavelength of theexposure light in a liquid is 1/n that of in air (where n is therefractive index of the liquid, normally about 1.2 to 1.6), and therebyimproving the resolution as well as increasing the depth of focus byapproximately n times.

Patent Document 1: PCT International Publication WO99/49504

Incidentally, it is important in an immersion exposure apparatus to forma liquid immersion area in a desired state. For example, if the liquidimmersion area on the substrate is not formed in a desired state, thenproblems will arise, such as the degradation of the pattern image or thefailure of the exposure light to reach the substrate, which will resultin a degradation of the exposure accuracy. In addition, it is alsoconceivable that a measurement process will be performed through theliquid using, for example, a measurement member and a measurementsensor, which are provided on the substrate stage; however, even in thatcase, the measurement accuracy will degrade if the liquid immersion areaon the substrate stage is not formed in a desired state.

In addition, if the liquid in the immersion area flows out of theimmersion area, or if the liquid used during exposure leaks and theninfiltrates and adheres to a position outside of the desired position,then there is a possibility that that liquid will cause problems, suchas a failure of apparatuses and members, electrical leakage, andrusting, thereby causing the degradation of exposure accuracy,measurement accuracy, and the like. If, unfortunately, a substrate isloaded onto a substrate holder in a state wherein, for example, liquidis adhering to that substrate holder that holds a substrate, then thatliquid will function as a lubricating film and cause the mispositioningof the substrate with respect to the substrate holder, thereby degradingexposure accuracy, measurement accuracy, and the like.

In addition, to satisfactorily form the liquid immersion area and tosatisfactorily recover the liquid, it is preferable to maintain theaffinity between the liquid and the substrate as well as the uppersurface of the substrate stage in an optimal state. If the liquid is notcompletely recovered and unfortunately remains, then that remainingliquid vaporizes and, for example, causes: thermal deformation of thesubstrate, the substrate stage, and the like; fluctuations in theenvironment (temperature, humidity) wherein the substrate is disposed;and fluctuations in the optical paths of the various measurement beamsthat measure the positional information of the substrate, and the like,thereby degrading exposure accuracy, measurement accuracy, and the like.In addition, after the remaining liquid vaporizes, a water residue (aso-called watermark) is unfortunately formed, which creates an errorfactor in the various measurements, and there is also a possibility thatthe substrate and the like will be contaminated by the generation offoreign matter.

DISCLOSURE OF THE INVENTION

The present invention was made considering such circumstances, and it isan object of the present invention to provide an exposure apparatus thatcan satisfactorily perform exposure and measurement processes through aliquid, and to provide a device manufacturing method.

To solve the abovementioned problems, the present invention adopts thefollowing constitution.

The exposure apparatus in accordance with the present invention is anexposure apparatus that exposes a substrate by emitting exposure lightonto the substrate through a projection optical system and a liquid,comprising a detection apparatus that detects whether the liquid ispresent on an object, which is disposed lower than a front end of theprojection optical system.

According to the present invention, the detection apparatus can be usedto detect whether the liquid is present on the object, which is disposedlower than the front end of the projection optical system. Accordingly,if, for example, an immersion area is not formed at a desired position,then it is possible to take appropriate measures, based on a detectionresult of the detection apparatus, in order to dispose the liquid at thedesired position, thereby maintaining high exposure and measurementaccuracies.

Likewise, if liquid flows out and adheres to a position outside of thedesired position, then it is possible to take appropriate measures basedon the detection result of the detection apparatus, e.g., stopping thesupply of the liquid, removing the liquid, and the like, therebymaintaining high exposure and measurement accuracies.

The exposure apparatus in accordance with the present invention is anexposure apparatus that exposes a substrate by emitting exposure lightonto the substrate through a projection optical system and a liquid,comprising a detection apparatus having an emitting portion that emitsdetection light to an immersion area formed between the projectionoptical system and an object disposed on an image plane side of theprojection optical system, and a light receiving portion that isdisposed at a predetermined position with respect to the detectionlight, wherein the detection apparatus obtains at least one of a sizeand a shape of the immersion area based on a light receiving result ofthe light receiving portion.

According to the present invention, the detection apparatus is used tooptically derive at least one of the size and the shape of the immersionarea, and it is thereby possible to take appropriate measures based onthe derived result in order to set the size and shape of the immersionarea to a desired state. Thereby, the optical path of the exposure lightcan be reliably filled with the liquid, and the exposure and measurementprocesses can be satisfactorily performed. In addition, even if there isa risk that, for example, the immersion area will spread excessively andthe liquid will flow out therefrom, it is possible to prevent theoccurrence of problems, such as the outflow of the liquid, by takingappropriate measures based on the detection result of the detectionapparatus.

The exposure apparatus in accordance with the present invention is anexposure apparatus that exposes a substrate by emitting exposure lightonto the substrate through a projection optical system and a liquid,comprising a shape detection apparatus that obtains a shape of theliquid on an object movable on an image plane side of the projectionoptical system.

According to the present invention, the shape detection apparatus isused to derive the shape of the liquid, and it is therefore possible toderive the affinity of the liquid for the object, specifically thecontact angle of the liquid with respect to the object. Accordingly,based on the derived result, it is possible to take appropriate measuresin order to maintain the affinity of the liquid for the substrate, theupper surface of the substrate stage, and the like in an optimal state,thereby maintaining high exposure and measurement accuracies.

The exposure apparatus in accordance with the present invention is anexposure apparatus that exposes a substrate by emitting exposure lightonto the substrate through a projection optical system and a liquid,comprising a detection apparatus that detects a contact angle of theliquid, on an upper surface of a substrate stage that holds thesubstrate, with respect to the upper surface of the substrate stage.

According to the present invention, it is possible to know the contactangle of the liquid with respect to the upper surface of the substratestage, and it is therefore possible to take appropriate measures basedon that result in order to maintain the affinity of the liquid for theupper surface of the substrate stage in an optimal state, therebymaintaining high exposure and measurement accuracies.

The device manufacturing method of the present invention uses theexposure apparatus recited above.

According to the present invention, it is possible to use the exposureapparatus, which is capable of satisfactorily performing the exposureand measurement processes through the liquid, to manufacture a devicethat exhibits the desired performance.

According to the present invention, the detection apparatus is used todetect the presence of liquid on an object disposed lower than the frontend of a projection optical system, the state of the immersion area, orthe shape or contact angle of the liquid, and it is therefore possibleto take optimal measures based on those detection results in order tomaintain high exposure and measurement accuracies. Accordingly, a devicethat has the desired performance can be manufactured.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic block diagram that depicts one embodiment of anexposure apparatus of the present invention.

FIG. 2 is a plan view of a substrate stage, viewed from above.

FIG. 3 is a side view that depicts one embodiment of a detectionapparatus according to the present invention.

FIG. 4 is a side view that depicts another embodiment of the detectionapparatus according to the present invention.

FIG. 5 is a plan view that depicts another embodiment of the detectionapparatus according to the present invention.

FIG. 6 is a plan view that depicts another embodiment of the detectionapparatus according to the present invention.

FIG. 7 is a flowchart diagram that depicts one example of an exposureoperation of the exposure apparatus.

FIG. 8 is a schematic diagram for explaining the relationship between adetection beam and an object surface.

FIG. 9 is a perspective view that depicts another embodiment of thedetection apparatus according to the present invention.

FIG. 10 is a side view that depicts another embodiment of the detectionapparatus according to the present invention.

FIG. 11 is a plan view of the same embodiment.

FIG. 12 is a side view that depicts another embodiment of the detectionapparatus according to the present invention.

FIG. 13A is a schematic diagram that depicts one example of theoperation of the exposure apparatus, and FIG. 13B is a schematic diagramthat likewise depicts one example of the operation of the exposureapparatus.

FIG. 14 is a side view that depicts another embodiment of the detectionapparatus according to the present invention.

FIG. 15 is a side view that depicts another embodiment of the detectionapparatus according to the present invention.

FIG. 16 is a side view that depicts one example of the operation of theexposure apparatus.

FIG. 17 is a perspective view that depicts another embodiment of thedetection apparatus according to the present invention.

FIG. 18A is a side view of FIG. 17, and FIG. 18B is a cross sectionalview along the B-B′ line in FIG. 17.

FIG. 19 is a plan view that depicts another embodiment of the detectionapparatus according to the present invention.

FIG. 20 is a flowchart that depicts one example of a process ofmanufacturing a semiconductor device.

BEST MODE FOR CARRYING OUT THE INVENTION

The following explains the exposure apparatus of the present invention,referencing the drawings, but the present invention is not limitedthereto.

FIG. 1 is a schematic diagram that depicts the structure of oneembodiment of the exposure apparatus according to the present invention.

In FIG. 1, an exposure apparatus EX has: a mask stage MST that supportsa mask M; a substrate stage PST that supports a substrate P; anillumination optical system IL that illuminates the mask M, which issupported by the mask stage MST, with an exposure light EL; a projectionoptical system PL that projects a pattern image of the mask Milluminated by the exposure light EL onto the substrate P supported bythe substrate stage PST so as to expose the substrate P; a detectionapparatus 60 that detects whether a liquid LQ is present on an object,which is disposed lower than the front end portion of the projectionoptical system PL on the image plane side thereof; and a controlapparatus CONT that provides overall control of the operation of theentire exposure apparatus EX. The control apparatus CONT is connected toa warning apparatus K that issues a warning when an abnormality arisesin the exposure process. Furthermore, the exposure apparatus EX has amain column 3 that supports the mask stage MST and the projectionoptical system PL. The main column 3 is installed on a base plate 4which is mounted horizontal to the floor surface. An upper side stepportion 3A and a lower side step portion 3B, which project inwardly, areformed in the main column 3.

The exposure apparatus EX of the present embodiment is a liquidimmersion type exposure apparatus that applies the liquid immersionmethod to substantially shorten the exposure wavelength so as to improvethe resolution, as well as substantially increase the depth of focus,and has a liquid supply mechanism 10 that supplies the liquid LQ ontothe substrate P, and a liquid recovery mechanism 20 that collects andrecovers the liquid LQ on the substrate P. At least during the transferof the pattern image of the mask M onto the substrate P, the exposureapparatus EX locally forms a (liquid) immersion area AR2, which islarger than a projection area AR1 and smaller than the substrate P, withthe liquid LQ, which is supplied by the liquid supply mechanism 10, on aportion of the substrate P that includes the projection area AR1 of theprojection optical system PL. Specifically, the exposure apparatus EXexposes the substrate P by filling a gap between an optical element 2 atthe front end portion of the projection optical system PL on the imageplane side and the front surface of the substrate P with the liquid LQ,and then projecting the pattern image of the mask M onto the substrate Pthrough the projection optical system PL and the liquid LQ that isbetween this projection optical system PL and the substrate P.

The present embodiment will now be explained as exemplified by a case ofusing a scanning type exposure apparatus (a so-called scanning stepper)as the exposure apparatus EX that exposes the substrate P with thepattern formed on the mask M, while synchronously moving the mask M andthe substrate P in mutually different (i.e., reverse) directions alongthe scanning direction. In the following explanation, the direction thatcoincides with an optical axis AX of the projection optical system PL isthe Z axial direction, the direction in which the mask M and thesubstrate P synchronously move (in the scanning direction) within theplane perpendicular to the Z axial direction is the X axial direction,and the direction (non-scanning direction) perpendicular to the Z axialdirection and the X axial direction is the Y axial direction. Inaddition, the rotational (inclination) directions around the X, Y, and Zaxes are the θX, θY, and θZ directions, respectively. Furthermore,“substrate” herein includes a semiconductor wafer coated with aphotoresist, which is a photosensitive material, and “mask” includes areticle wherein a device pattern, which is reduction-projected onto thesubstrate, is formed.

The illumination optical system IL is supported by a support column 5,which is fixed to an upper portion of the main column 3. Theillumination optical system IL illuminates the mask M, which issupported by the mask stage MST, with the exposure light EL, and has: anexposure light source; an optical integrator that uniformizes theluminous flux intensity (i.e., illuminance) of the light beam emittedfrom the exposure light source; a condenser lens that condenses theexposure light EL from the optical integrator; a relay lens system; avariable field stop that sets an illumination region on the mask Milluminated by the exposure light EL to be slit-shaped; and the like.The illumination optical system IL illuminates the prescribedillumination region on the mask M with the exposure light EL, which hasa uniform luminous flux intensity distribution. Examples of light thatcan be used as the exposure light EL emitted from the illuminationoptical system IL include: deep ultraviolet light (DUV light), such asthe bright lines (g, h, and i lines) emitted from a mercury lamp forexample, and KrF excimer laser light (248 nm wavelength); and vacuumultraviolet light (VUV light), such as ArF excimer laser light (193 nmwavelength) and F₂ laser light (157 nm wavelength). ArF excimer laserlight is used in the present embodiment.

In the present embodiment, pure water is used as the liquid LQ. Purewater is capable of transmitting not only ArF excimer laser light, butalso deep ultraviolet light (DUV light), such as the bright lines (g, h,and i lines) emitted from, for example, a mercury lamp, and KrF excimerlaser light (248 nm wavelength).

The mask stage MST supports the mask M and has an open portion 34A atits center portion, which the pattern image of the mask M passesthrough. A mask surface plate 31 is supported on the upper side stepportion 3A of the main column 3 via a vibration isolating unit 6. Anopen portion 34B, which the pattern image of the mask M passes through,is also formed at the center portion of the mask surface plate 31. Aplurality of gas bearings (air bearings) 32, which are noncontactbearings, is provided at the lower surface of the mask stage MST. Themask stage MST is contactlessly supported by the air bearings 32 withrespect to an upper surface (guide surface) 31A of the mask surfaceplate 31, and is two-dimensionally movable by the mask stage drivemechanism, such as a linear motor, within a plane perpendicular to theoptical axis AX of the projection optical system PL, i.e., within the XYplane, and is finely rotatable about the θZ direction. Movable mirrors35 are provided to the mask stage MST. In addition, a laserinterferometer 36 is provided at a position opposing each movable mirror35. The laser interferometers 36 measure in real time the positions inthe two-dimensional directions as well as the rotational angle in the θZdirection (depending on the case, including the rotational angles in theθX and θY directions) of the mask M on the mask stage MST, and outputthese measurement results to the control apparatus CONT. The controlapparatus CONT drives the mask stage drive mechanism based on themeasurement results of the laser interferometers 36, thereby controllingthe position of the mask M, which is supported by the mask stage MST.

The projection optical system PL projects the pattern of the mask M ontothe substrate P at a prescribed projection magnification β so as toexpose the substrate P, and has a plurality of optical elements, whichincludes an optical element (lens) 2 provided at the front end portionthereof on the substrate P side, that is supported by a lens barrel PK.In the present embodiment, the projection optical system PL is areduction system that has a projection magnification P of, for example,¼ or ⅕. Furthermore, the projection optical system PL may be an equalmagnification system or an enlargement system. In addition, theprojection optical system PL may be a reflecting system, which does notinclude refracting elements, a refracting system, which does not includereflecting elements, or a catadioptric system, which includes bothrefracting elements and reflecting elements. A flange portion FLG isprovided at the outer circumferential portion of the lens barrel PK. Inaddition, a lens barrel surface plate 8 is supported by the lower sidestep portion 3B of the main column 3 via a vibration isolating unit 7.Furthermore, the projection optical system PL is supported by the lensbarrel surface plate 8 due to the flange portion FLG of the projectionoptical system PL engaging with the lens barrel surface plate 8.

In addition, the optical element 2 at the front end portion of theprojection optical system PL of the present embodiment is exposed to theexterior of the lens barrel PK, and makes contact with the liquid LQ ofthe immersion area AR2. The optical element 2 is made of calciumfluorite. The liquid LQ can adhere to substantially the entire surfaceof a liquid contact surface 2A of the optical element 2 because liquidcontact surface 2A, which is made of calcium fluorite, has a strongaffinity for water. Namely, because the liquid (water) LQ supplied inthe present embodiment has a strong affinity for the liquid contactsurface 2A of the optical element 2, the liquid contact surface 2A ofthe optical element 2 and the liquid LQ have strong adhesioncharacteristics, and therefore the optical path between the opticalelement 2 and the substrate P can be reliably filled with the liquid LQ.Furthermore, the optical element 2 may be made of silica glass, whichalso has a strong affinity for water. In addition, the liquid contactsurface 2A of the optical element 2 may be given hydrophilic (lyophilic)treatment in order to further raise its affinity for the liquid LQ.

The substrate stage PST is provided so that it is capable of holding andmoving the substrate P via a substrate holder PH, and is also providedso that it is capable of moving with respect to the projection opticalsystem PL. The substrate holder PH holds the substrate P either by avacuum suction system or an electrostatic chuck system. A plurality ofgas bearings (air bearings) 42, which are noncontact bearings, areprovided to the lower surface of the substrate stage PST. A substratesurface plate 41 is supported on the base plate 4 via vibrationisolating units 9. Each of the air bearings 42 has a blowout port 42Bthat blows a gas (air) out toward an upper surface (guide surface) 41Aof the substrate surface plate 41, as well as intake ports 42A thatsuction the gas between the lower surface (bearing surface) of thesubstrate stage PST and the guide surface 41A and that maintain a fixedgap therebetween due to the equilibrium between the repellent forcecaused by blowing the gas out from the blowout port 42B and the suctionforce of the intake ports 42A. Namely, the substrate stage PST iscontactlessly supported by the air bearings 42 with respect to an uppersurface (guide surface) 41A of the substrate surface plate 41, and isfinely rotatable in the θZ direction and two-dimensionally movablewithin a plane perpendicular to the optical axis AX of the projectionoptical system PL, i.e., within the XY plane, by a substrate stage drivemechanism, such as a linear motor. Furthermore, the substrate holder PHis provided so that it is also capable of moving in the Z axialdirection as well as the θX and θY directions via a holder drivemechanism. The control apparatus CONT controls the substrate stage drivemechanism.

In addition, the exposure apparatus EX has a focus leveling detectionsystem (not shown) that detects the position of the front surface of thesubstrate P that is supported by the substrate stage PST. Furthermore,the system disclosed in, for example, Japanese Published UnexaminedPatent Application No. H8-37149 can be used to constitute the focusleveling detection system. The detection result of the focus levelingdetection system is outputted to the control apparatus CONT. Based onthe detection result of the focus leveling detection system, the controlapparatus CONT can detect the positional information of the frontsurface of the substrate P in the Z axial direction, as well as theinclination information of the substrate P in the θX and θY directions.

The control apparatus CONT aligns the front surface of the substrate Pwith the image plane of the projection optical system PL by using anauto focus system and an auto leveling system, and by driving the holderdrive mechanism as well as controlling the focus position (Z position)and inclination angle of the front surface of the substrate P, which isheld on the substrate holder PH.

A recessed portion 1 is provided on the substrate stage PST, and thesubstrate holder PH is disposed in that recessed portion 1. Furthermore,an upper surface 43 of the substrate stage PST is a flat surface that isconstituted so that it is substantially the same height as (flush with)the front surface of the substrate P, which is supported by thesubstrate holder PH.

Movable mirrors 45 are provided to the substrate stage PST. In addition,a laser interferometer 46 is provided at a position opposing eachmovable mirror 45. The laser interferometers 46 measure in real time thepositions in the two-dimensional directions as well as the rotationalangle of the substrate P on the substrate stage PST, and output thesemeasurement results to the control apparatus CONT. The control apparatusCONT drives the substrate stage drive mechanism, which includes a linearmotor, based on the measurement results of the laser interferometers 46,and thereby positions the substrate P, which is supported on thesubstrate stage PST, in the X and Y axial directions.

In addition, the substrate stage PST is supported so that it is freelymovable in the X axial direction by an X guide stage 44. The substratestage PST is movable by a prescribed stroke in the X axial direction byan X linear motor 47 while being guided by the X guide stage 44. The Xlinear motor 47 has a stator 47A provided to the X guide stage 44extending in the X axial direction, and a slider 47B providedcorresponding to this stator 47A and fixed to the substrate stage PST.Furthermore, the substrate stage PST moves in the X axial direction bydriving the slider 47B with respect to the stator 47A. Here, thesubstrate stage PST is contactlessly supported by a magnetic guidehaving an actuator and a magnet that maintains a predetermined gap inthe Z axial direction with respect to the X guide stage 44. The X linearmotor 47 moves the substrate stage PST in the X axial direction in astate in which it is contactlessly supported by the X guide stage 44.

The ends of the X guide stage 44 in the longitudinal direction areprovided with a pair of Y linear motors 48, 48 capable of moving this Xguide stage 44 along with the substrate stage PST in the Y axialdirection. The Y linear motors 48, 48 are provided at opposite ends ofthe X guide stage 44 in the longitudinal direction, each Y linear motor48 has a slider 48B and a stator 48A, which is provided corresponding tothe slider 48B.

Furthermore, the X guide stage 44 along with the substrate stage PSTmoves in the Y axial direction by driving the sliders 48B with respectto the stators 48A. In addition, the X guide stage 44 can also berotated in the θZ direction by adjusting the respective drives of the Ylinear motors 48. Accordingly, the substrate stage PST is movablesubstantially integrally with the X guide stage 44 in the Y axialdirection and the θZ direction by these Y linear motors 48, 48.

Guide portions 49 are each formed in an L shape in a front view andguide the movement of the X guide stage 44 in the Y axial direction;furthermore, the guide portions 49 are respectively provided on oppositesides of the substrate surface plate 41 in the X axial direction. Eachguide portion 49 is supported on the base plate 4. In the presentembodiment, the stator 48A of each Y linear motor 48 is provided on aflat portion 49B of the corresponding guide portion 49. Further, arecessed guided member 50 is provided on the lower surface of the Xguide stage 44 at each end thereof in the longitudinal direction. Eachguide portion 49 is provided so that it engages with the respectiveguided member 50, and so that an upper surface (the guide surface) 49Aof each guide portion 49 opposes the inner surface of the respectiveguided member 50. The guide surface 49A of each guide portion 49 isprovided with a gas bearing (air bearing) 51, which is a noncontactbearing, and the X guide stage 44 is contactlessly supported withrespect to the guide surfaces 49A.

In addition, a gas bearing (air bearing) 52, which is a noncontactbearing, is interposed between the stator 48A of each Y linear motor 48and the flat portion 49B of the respective guide portion 49;additionally, each stator 48A is contactlessly supported by therespective air bearing 52 with respect to the flat portion 49B of therelevant guide portion 49. Consequently, by the law of conservation ofmomentum, each stator 48A moves in the −Y direction (+Y direction) inresponse to the movement of the X guide stage 44 and the substrate stagePST in the +Y direction (−Y direction). The movement of the stator 48Aoffsets the reaction force attendant with the movement of the X guidestage 44 and the substrate stage PST, and also prevents a change in theposition of the center of gravity. Namely, each stator 48A functions asa so-called counter mass.

The liquid supply mechanism 10 supplies the prescribed liquid LQ on theimage plane side of the projection optical system PL, and has: a liquidsupply portion 11 that is capable of feeding the liquid LQ; and supplypipes 13 (13A, 13B), each having one end portion that is connected tothe liquid supply portion 11. The liquid supply portion 11 has a tankthat stores the liquid LQ, a pressure pump, and the like. The controlapparatus CONT controls the liquid supply operation of the liquid supplyportion 11. The liquid supply mechanism 10 supplies the liquid LQ, whichis controlled at a prescribed temperature (e.g., 23° C.), onto thesubstrate P when forming the immersion area AR2 thereon. Furthermore,the exposure apparatus EX is not necessarily equipped with the tank, thepressure pump, and the like of the liquid supply portion 11, and suchcan be substituted by the equipment at, for example, the plant where theexposure apparatus EX is installed.

In addition, it is preferable to control the temperature stability anduniformity of the liquid LQ supplied from the liquid supply mechanism 10to approximately 0.01° to 0.001° C.

Valves 15, which open and close the passageways of the supply pipes 13A,13B, are respectively provided along the supply pipes 13A, 13B. Thecontrol apparatus CONT controls the operation of opening and closing thevalves 15. Furthermore, the valves 15 in the present embodiment areso-called normally closed systems, which mechanically block thepassageways of the supply pipes 13A, 13B if the drive source (powersupply) of the exposure apparatus EX (the control apparatus CONT) stopsdue to, for example, a power outage.

The liquid recovery mechanism 20 collects and recovers the liquid LQ onthe image plane side of the projection optical system PL, and has: aliquid recovery portion 21 that is capable of collecting the liquid LQ;and recovery pipes 23 (23A, 23B), each having one end portion that isconnected to the liquid recovery portion 21. The liquid recovery portion21 is provided with: a vacuum system (a suction apparatus), e.g., avacuum pump and the like; a gas-liquid separator that separates thecollected liquid LQ and gas; a tank that stores the recovered liquid LQ;and the like. Furthermore, instead of providing the exposure apparatusEX with a vacuum pump, the vacuum system at the plant where the exposureapparatus EX is disposed may be used as the vacuum system. The controlapparatus CONT controls the liquid recovery operation of the liquidrecovery portion 21. To form the immersion area AR2 on the substrate P,the liquid recovery mechanism 20 collects a prescribed amount of theliquid LQ on the substrate P that was supplied by the liquid supplymechanism 10.

A passageway forming member 70 is disposed in the vicinity of, among theplurality of optical elements that constitutes the projection opticalsystem PL, the optical element 2 that contacts the liquid LQ. Thepassageway forming member 70 is an annular member provided above thesubstrate P (above the substrate stage PST) so that it surrounds theside surface of the optical element 2. A gap is provided between theoptical element 2 and the passageway forming member 70, and thepassageway forming member 70 is supported by a prescribed supportmechanism so that it is vibrationally isolated from the optical element2.

The passageway forming member 70 can be formed from, for example,aluminum, titanium, stainless steel, duralumin, or an alloy containingsuch. Alternatively, the passageway forming member 70 may be formedusing a transparent member (an optical member) that has lighttransmitting properties, such as glass (silica glass).

The passageway forming member 70 is provided above the substrate P(above the substrate stage PST), and has liquid supply ports 12 (12A,12B) disposed so that they oppose the front surface of the substrate P.In the present embodiment, the passageway forming member 70 has twoliquid supply ports 12A, 12B. The liquid supply ports 12A, 12B areprovided to a lower surface 70A of the passageway forming member 70.

In addition, the interior of the passageway forming member 70 has supplypassageways corresponding to the liquid supply ports 12A, 12B. Theplurality (two) of supply pipes 13A, 13B is provided corresponding tothe liquid supply ports 12A, 12B and the supply passageways.Furthermore, one end portion of each of the supply passageways isconnected to the liquid supply portion 11 via the supply pipes 13A, 13B,respectively, and the other end portion of each is connected to theliquid supply ports 12A, 12B, respectively.

In addition, flow controllers 16 (16A, 16B), which are called mass flowcontrollers and control the amount of liquid per unit of time fed fromthe liquid supply portion 11 to each of the liquid supply ports 12A,12B, are provided along the two supply pipes 13A, 13B, respectively. Thecontrol of the amount of liquid by the flow controllers 16A, 16B isperformed based on a command signal from the control apparatus CONT.

Furthermore, the passageway forming member 70 is provided above thesubstrate P (the substrate stage PST), and has liquid recovery ports 22(22A, 22B) disposed so that they oppose the front surface of thesubstrate P.

In the present embodiment, the passageway forming member 70 has twoliquid recovery ports 22A, 22B. The liquid recovery ports 22A, 22B areprovided to the lower surface 70A of the passageway forming member 70.

In addition, the interior of the passageway forming member 70 hasrecovery passageways corresponding to the liquid recovery ports 22A,22B. In addition, a plurality (two) of the recovery pipes 23A, 23B isprovided corresponding to the liquid recovery ports 22A, 22B and therecovery passageways. Furthermore, one end portion of each of therecovery passageways is connected to the liquid recovery portion 21 viathe recovery pipes 23A, 23B, respectively, and the other end portion ofeach is connected to the liquid recovery ports 22A, 22B, respectively.

In the present embodiment, the passageway forming member 70 constitutesa portion of both the liquid supply mechanism 10 and the liquid recoverymechanism 20. Furthermore, the liquid supply port 12A and the liquidsupply port 12B, which constitute the liquid supply mechanism 10, arerespectively provided at positions on opposite sides of the projectionarea AR1 of the projection optical system PL in the X axial direction sothat the projection area AR1 is interposed therebetween, and the liquidrecovery port 22A and the liquid recovery port 22B, which constitute theliquid recovery mechanism 20, are respectively provided on the outersides of the liquid supply ports 12A, 12B of the liquid supply mechanism10 with respect to the projection area AR1 of the projection opticalsystem PL.

The control apparatus CONT controls the operation of the liquid supplyportion 11 and the flow controllers 16. When supplying the liquid LQonto the substrate P, the control apparatus CONT feeds the liquid LQfrom the liquid supply portion 11 and supplies the liquid LQ onto thesubstrate P from the liquid supply ports 12A, 12B, which are providedabove the substrate P, through the supply pipes 13A, 13B and the supplypassageways. At this time, the liquid supply port 12A and the liquidsupply port 12B are disposed respectively on opposite sides of theprojection area AR1 of the projection optical system PL so that theprojection area AR1 is interposed therebetween, and the liquid LQ can besupplied from both sides of the projection area AR1 through those liquidsupply ports 12A, 12B. In addition, the amounts of the liquid LQsupplied per unit of time onto the substrate P from the liquid supplyports 12A, 12B can be separately controlled by the flow controllers 16A,16B, which are respectively provided to the supply pipes 13A, 13B.

The control apparatus CONT controls the operation of recovering theliquid by the liquid recovery portion 21. The control apparatus CONT cancontrol the amount of the liquid recovered per unit of time by theliquid recovery portion 21. The liquid LQ on the substrate P collectedfrom the liquid recovery ports 22A, 22B, which are provided above thesubstrate P, is stored into the liquid recovery portion 21 via therecovery passageway of the passageway forming member 70 and the recoverypipes 23A, 23B.

Furthermore, in the present embodiment, the supply pipes 13A, 13B areconnected to one liquid supply portion 11, but a plurality (herein, two)of liquid supply portions 11 corresponding to the number of the supplypipes may be provided, and the supply pipes 13A, 13B may be respectivelyconnected to the plurality of liquid supply portions 11. In addition,the recovery pipes 23A, 23B are connected to one liquid recovery portion21, but a plurality (herein, two) of the liquid recovery portions 21corresponding to the number of recovery pipes may be provided, and therecovery pipes 23A, 23B may be respectively connected to the pluralityof liquid recovery portions 21.

The liquid contact surface 2A of the optical element 2 of the projectionoptical system PL and the lower surface (liquid contact surface) 70A ofthe passageway forming member 70 are lyophilic (hydrophilic). In thepresent embodiment, the optical element 2 and the liquid contact surfaceof the passageway forming member 70 are lyophilically treated, and thatlyophilic treatment makes the optical element 2 and the liquid contactsurface of the passageway forming member 70 lyophilic. In other words,of the surfaces of the members that oppose the surface to be exposed(front surface) of the substrate P held by the substrate stage PST, atleast the liquid contact surface is lyophilic. Because the liquid LQ inthe present embodiment is water, which has a high polarity, the opticalelement 2 and the liquid contact surface of the passageway formingmember 70 can be lyophilically treated (hydrophilically treated) toprovide lyophilicity by, for example, forming a thin film with asubstance that has a molecular structure having a high polarity, such asalcohol. Namely, if using water as the liquid LQ, then it is preferableto perform a process of providing a portion having a molecular structurethat has a high polarity, such as the OH group, at the liquid contactsurface. Alternatively, the liquid contact surface can be provided witha lyophilic material, such as MgF₂, Al₂O₃, SiO₂, and the like.

The lower surface (surface facing the substrate P side) 70A of thepassageway forming member 70 is substantially a flat surface, the lowersurface (liquid contact surface) 2A of the optical element 2 is also aflat surface, and the lower surface 70A of the passageway forming member70 is substantially flush with the lower surface 2A of the opticalelement 2. Thereby, the immersion area AR2 can be satisfactorily formedwithin the desired area.

Furthermore, the mechanism for locally forming the immersion area AR2 onthe substrate P (the substrate stage PST) is not limited to the onediscussed above, and it is possible to adopt the mechanism disclosed in,for example, U.S. Patent Application Publication No. 2004/020782, whichis hereby incorporated by reference in its entirety to the extentpermitted by the national laws and regulations of the designated states(or elected states) designated by the present international patentapplication.

The detection apparatus 60 detects whether the liquid LQ is present onthe substrate P or the substrate stage PST, which is disposed lower thanthe front end portion of the projection optical system PL, and has alight emitting portion 61 that emits a detection beam La, and a lightreceiving portion 62 disposed at a prescribed position with respect tothe detection beam La. In the present embodiment, the light emittingportion 61 is provided to the main column 3 at a prescribed position,and the light receiving portion 62 is provided to the main column 3 at aposition opposing the light emitting portion 61 so that the projectionarea AR1 of the projection optical system PL is interposed therebetween.The detection beam La emitted from the light emitting portion 61 of thedetection apparatus 60 is set so that it is radiated substantiallyparallel to the front surface of the substrate P and the upper surface43 of the substrate stage PST, which is substantially flush with thefront surface of the substrate P. The detection beam La emitted from thelight emitting portion 61 passes below the optical element 2, which isprovided at the front end portion of the projection optical system PL.

FIG. 2 is a plan view of the substrate stage PST, which is capable ofholding and moving the substrate P, viewed from above.

In FIG. 2, the movable mirrors 45 are respectively disposed at twomutually perpendicular edge portions of the substrate stage PST, whichis rectangular in a plan view. In addition, the projection area AR1 ofthe projection optical system PL is set to a rectangular shape in a planview, wherein the longitudinal direction is the Y axial direction andthe latitudinal (i.e., shorter side) direction is the X axial direction.

Within the detection apparatus 60, the light emitting portion 61 thatemits the detection beam La is fixed (in the present embodiment, to themain column 3) at a prescribed position away from the substrate stagePST on the −X side, and the light receiving portion 62 is fixed (to themain column 3) at a prescribed position away from the substrate stagePST on the +X side. Furthermore, the light emitting portion 61 of thedetection apparatus 60 emits the detection beam La from the outer sideof the substrate stage PST, and, based on the light receiving result ofthe light receiving portion 62, the detection apparatus 60 detects theliquid LQ on the substrate P and on the substrate stage PST. Namely, thedetection apparatus 60 optically detects the liquid LQ from the outerside of the substrate stage PST, which is capable of holding and movingthe substrate P.

The recessed portion 1 is formed at substantially the center portion ofthe substrate stage PST, and the substrate holder PH, which holds thesubstrate P, is disposed in the recessed portion 1. In the substratestage PST, the upper surface 43 outside of the recessed portion 1 is setat substantially the same height (flush with) as the front surface ofthe substrate P held by the substrate holder PH. Because the uppersurface 43, which is substantially flush with the front surface of thesubstrate P, is provided around the substrate P, it is possible to holdthe liquid LQ on the image plane side of the projection optical systemPL and thereby satisfactorily form the immersion area AR2, even whenperforming an immersion exposure of an edge area E of the substrate P.

In the present embodiment, the detection beam La is set below theoptical element 2 at the front end portion of the projection opticalsystem PL, so that it passes through the projection area AR1 of theprojection optical system PL, i.e., the optical path of the exposurelight EL. More specifically, the detection beam La is set so that itpasses between the optical element 2 and the substrate P (the substratestage PST). Furthermore, the detection beam La may be provided so thatit passes through an area outside of the optical path of the exposurelight EL. Furthermore, the detection beam La is emitted substantiallyparallel to the front surface of the substrate P and the upper surface43 of the substrate stage PST.

In addition, the upper surface 43 of the substrate stage PST is given aliquid repellant treatment and is therefore liquid repellant. Examplesof liquid repellent treatments for the upper surface 43 include coatingit with a liquid repellent material, e.g., a fluororesin material or anacrylic resin material, as well as affixing a thin film made of theabovementioned liquid repellent material. A material that is insolublein the liquid LQ is used as the liquid repellent material for providingliquid repellency. Furthermore, all or portion of the substrate stagePST may be made of a liquid repellent material, such as a fluororesinsuch as polytetrafluoroethylene (Teflon™). In addition, a liquidrepellent plate member, which is made of the abovementionedpolytetrafluoroethylene and the like, may be replaceably disposed on theupper surface of the substrate stage PST. In the present embodiment, aplate member 43P, which has the upper surface 43, is replaceablydisposed on the substrate stage PST.

Furthermore, a gap is formed between the plate member 43P and a sidesurface PB of the substrate P, which is held by the substrate holder PH;however, this is a small gap on the order of a few millimeters, whichsuppresses the problem of the liquid LQ entering that gap, due to theaction of the surface tension of the liquid LQ and the like.

The liquid supply port 12A and the liquid supply port 12B arerespectively provided on opposite sides of the projection area AR1 ofthe projection optical system PL so that the projection area AR1 isinterposed therebetween in the X axial direction (the scanningdirection). Specifically, the liquid supply port 12A is provided to thelower surface 70A of the passageway forming member 70 on one side (the−X side) of the projection area AR1 in the scanning direction, and theliquid supply port 12B is provided on the other side (the +X side). Inother words, the liquid supply port 12A and the liquid supply port 12Bare provided respectively on opposite sides of and near to theprojection area AR1 so that it is interposed therebetween in thescanning direction (the Y axis). The liquid supply ports 12A, 12B areeach formed as a substantially U-shaped (arcuate) slit (in a plan view)extending in the Y axial direction. Furthermore, the length of each ofthe liquid supply ports 12A, 12B in the Y axial direction is at leastlonger than the length of the projection area AR1 in the Y axialdirection. The liquid supply ports 12A, 12B are provided so that theysurround at least the projection area AR1. The liquid supply mechanism10 is capable of simultaneously supplying the liquid LQ to both sides ofthe projection area AR1 through the liquid supply ports 12A, 12B.

The liquid recovery port 22A and the liquid recovery port 22B arerespectively provided on the outer sides of the liquid supply ports 12A,12B of the liquid supply mechanism 10 with respect to the projectionarea AR1 of the projection optical system PL, and are respectivelyprovided on opposite sides of the projection area AR1 of the projectionoptical system PL so that the projection area AR1 is interposed betweenthe liquid recovery ports 22A, 22B in the X axial direction (thescanning direction). Specifically, the liquid recovery port 22A isprovided to the lower surface 70A of the passageway forming member 70 onone side (the −X side) of the projection area AR1 in the scanningdirection, and the liquid recovery port 22B is provided on the otherside (the +X side). The liquid recovery ports 22A, 22B are each formedin a substantially U-shaped (arcuate) slit (in a plan view) extending inthe Y axial direction. The liquid recovery ports 22A, 22B are providedso that they surround the projection area AR1 of the projection opticalsystem PL as well as the liquid supply ports 12A, 12B.

Furthermore, the immersion area AR2, which is filled with the liquid LQ,is locally formed on portion of the substrate P and within an area thatis substantially surrounded by the two liquid recovery ports 22A, 22B sothat the projection area AR1 is included therein. Furthermore, theimmersion area AR2 should cover at least the projection area AR1, butthe entire area surrounded by at least the two liquid recovery ports22A, 22B does not need to be an immersion area.

Furthermore, the present embodiment is constituted so that one liquidsupply port 12 is provided on each side of the projection area AR1, buta plurality thereof may be provided, the number of which is arbitrary.Likewise, a plurality of the liquid recovery ports 22 may be provided.In addition, the liquid supply ports 12, which are provided on oppositesides of the projection area AR1, are formed so that they aresubstantially the same size (length), but may be of a size differentfrom one another. Likewise, the liquid recovery ports 22, which areprovided on opposite sides of the projection area AR1, may be ofmutually differing sizes. In addition, the slit width of the supplyports 12 and the slit width of the recovery ports 22 may be the same,the slit width of the recovery ports 22 may be larger than the slitwidth of the supply ports 12, or, conversely, the slit width of therecovery ports 22 may be smaller than the slit width of the supply ports12.

In addition, a fiducial member 300 is disposed on the substrate stagePST at a prescribed position on the outer side of the substrate P. Thefiducial member 300 is provided with a prescribed positionalrelationship between a fiducial mark PFM detected by the substratealignment system constituted as disclosed in, for example, JapanesePublished Unexamined Patent Application No. H4-65603, and a fiducialmark MFM detected by the mask alignment system constituted as disclosedin, for example, Japanese Published Unexamined Patent Application No.H7-176468. An upper surface 301A of the fiducial member 300 issubstantially a flat surface and is provided at substantially the sameheight as (flush with) the front surface of the substrate P and theupper surface 43 of the substrate stage PST. The substrate alignmentsystem, which is provided in the vicinity of the substrate stage PST,also detects alignment marks on the substrate P. In addition, the maskalignment system is provided in the vicinity of the mask stage MST, anddetects, through the mask M and the projection optical system PL, thefiducial mark MFM on the substrate stage PST.

In addition, a luminous flux intensity nonuniformity sensor 400 of thetype disclosed in, for example, Japanese Published Patent ApplicationNo. S57-117238 is disposed as a measurement sensor on the substratestage PST at a prescribed position on the outer side of the substrate P.The luminous flux intensity nonuniformity sensor 400 has an upper plate401, which is rectangular in a plan view. An upper surface 401A of theupper plate 401 is substantially a flat surface and is provided atsubstantially the same height as (flush with) the front surface of thesubstrate P and the upper surface 43 of the substrate stage PST. Apinhole portion 470, wherethrough light can pass, is provided in theupper surface 401A of the upper plate 401. The upper surface 401A thatis outside of the pinhole portion 470 is covered with a shieldingmaterial, such as chrome.

In addition, a spatial image measuring sensor 500 of the type disclosedin, for example, Japanese Published Patent Application No. 2002-14005 isprovided as a measurement sensor on the substrate stage PST at aprescribed position on the outer side of the substrate P. The spatialimage measuring sensor 500 has an upper plate 501, which is rectangularin a plan view. An upper surface 501A of the upper plate 501 issubstantially a flat surface and is provided at substantially the sameheight as (flush with) the front surface of the substrate P and theupper surface 43 of the substrate stage PST. A slit portion 570,wherethrough light can pass, is provided in the upper surface 501A ofthe upper plate 501. The upper surface 501A that is outside of the slitportion 570 is covered with a shielding material, such as chrome.

In addition, although not shown, an irradiance sensor (an illuminancesensor) of the type disclosed in, for example, Japanese Published PatentApplication No. H11-16816 is also provided on the substrate stage PST,and an upper surface of an upper plate of that irradiance sensor isprovided at substantially the same height as (flush with) the frontsurface of the substrate P and the upper surface 43 of the substratestage PST.

Thus, the upper surface 43 of the substrate stage PST is disposed atsubstantially the same height as (flush with) both the fiducial member300 and the sensors 400, 500, and is liquid-repellent. Furthermore, theupper surface of each movable mirror 45 is also disposed atsubstantially the same height as (flush with) the upper surface 43 ofthe substrate stage PST, and both the upper surface and the reflectingsurface of each movable mirror 45 is liquid-repellent. Thereby, it isnot only possible to increase the range of movement of the substratestage PST in the state wherein the immersion area AR2 is formed, but,even if the liquid adheres to the fiducial member 300, the sensors 400,500, the upper surfaces or reflecting surfaces of the movable mirrors 45or the like, it is also possible to easily eliminate that adheredliquid.

Furthermore, the fiducial member 300, the upper plates 401, 501, and thelike are constituted so that they are detachable from the substratestage PST, and can be replaced if, for example, the liquid repellency oftheir upper surfaces deteriorates.

FIG. 3 is a side view that depicts one example of a state wherein thedetection apparatus 60 is detecting the liquid LQ. As depicted in FIG.3, the detection apparatus 60 emits the detection beam La substantiallyparallel to the upper surface 43 of the substrate stage PST and thefront surface of the substrate P, which is held by the substrate holderPH. Furthermore, the detection apparatus 60 detects, based on the lightreceiving result of the light receiving portion 62, whether the liquidLQ is present on the substrate P or the substrate stage PST.

The light emitting portion 61 and the light receiving portion 62 aremutually opposing, and the detection beam La emitted from the lightemitting portion 61 arrives at the light receiving portion 62 whichreceives a prescribed quantity (intensity) of the relevant light. Atthis time, if, for example, a liquid droplet (a water droplet) of theliquid LQ is disposed on the substrate P or on the substrate stage PST,as depicted in FIG. 3, and the liquid LQ is irradiated by the detectionbeam La, then that detection beam La is refracted, scattered, orabsorbed by the liquid LQ. Accordingly, if the liquid LQ is present inthe optical path of the detection beam La, then the light quantity(light intensity) received by the light receiving portion 62 decreases,or the detection beam La no longer arrives at the light receivingportion 62. Accordingly, the detection apparatus 60 can detect, based onthe light receiving result (the amount of light received) of the lightreceiving portion 62, whether the liquid LQ is present in the opticalpath of the detection beam La. Furthermore, by detecting whether theliquid LQ is present in the optical path of the detection beam La, thedetection apparatus 60 can detect whether the liquid LQ is present onthe substrate stage PST or on the substrate P, which are disposed lowerthan the front end portion of the projection optical system PL.

In addition, by emitting the detection beam La while moving thedetection beam La of the detection apparatus 60 and the substrate stagePST relative to one another, it is possible to detect whether the liquidLQ is present in a comparatively large area on the substrate stage PST,including on the substrate P.

Furthermore, by emitting the detection beam La while moving thedetection beam La and the substrate stage PST relative to one another ina state wherein the liquid LQ is disposed on (or adhering to) thesubstrate P or the substrate stage PST, it is possible to derive theposition of the liquid LQ on the substrate P or the substrate stage PST.In other words, the detection beam La is emitted while moving thesubstrate stage PST as well as while monitoring the position thereofusing the laser interferometer 46. Based on the position measurementresult of the laser interferometer 46 and the light receiving result ofthe light receiving portion 62 of the detection apparatus 60, thecontrol apparatus CONT can derive the position of the liquid LQ in thecoordinate system stipulated by the laser interferometer 46.

In addition, in FIG. 3, a constitution is adopted wherein the lightemitting portion 61 and the light receiving portion 62 are respectivelydisposed on opposite sides of the substrate stage PST so that thesubstrate stage PST is interposed therebetween in the X axial direction,and the position of the liquid LQ on the substrate P or on the substratestage PST in the Y axial direction is detected by moving the substratestage PST in the Y axial direction while emitting the detection beam Lafrom the light emitting portion 61; however, by respectively disposingthe light emitting portion 61 and the light receiving portion 62 onopposite sides of the substrate stage PST so that the substrate stagePST is interposed therebetween in the Y axial direction, both theposition and the area of the liquid LQ on the substrate P or thesubstrate stage PST in the X axial direction can be detected by movingthe substrate stage PST in the X axial direction while emitting thedetection beam La from the light emitting portion 61.

In addition, in FIG. 3, a constitution is adopted wherein the lightemitting portion 61 and the light receiving portion 62 of the detectionapparatus 60 are disposed opposing one another; however, as depicted inFIG. 4, optical members 63, 64, which serve as bending portions thatbend the optical path of the detection beam La, may be provided in theoptical path of the detection beam La of the detection apparatus 60. Inso doing, the detection beam La can be emitted to a desired positionwhile disposing the light emitting portion 61 and the light receivingportion 62 at arbitrary positions, which can increase the degrees offreedom of the arrangement of the various members and equipment thatconstitute the detection apparatus 60, as well as the degrees of freedomof the overall design of the exposure apparatus EX.

Furthermore, the detection beam La emitted from the light emittingportion 61 may be incident onto the incident end of an optical fiber,and the detection beam La that emitted from the output end of thatoptical fiber may be emitted. In addition, an optical fiber may beconnected to the light receiving portion 62, and the detection beam Lamay be received thereby through that optical fiber.

In addition, in the constitution discussed above, the position of theliquid LQ on the substrate P or on the substrate stage PST is detectedby performing detection while moving the substrate P and the substratestage PST with respect to the detection beam La of the detectionapparatus 60; however, as depicted in FIG. 5, the position of the liquidLQ on the substrate P or on the substrate stage PST can also be derivedby emitting a plurality of detection beams La in a two dimensionalmatrix.

In FIG. 5, the detection apparatus 60 has: a first light emittingportion 61X, which is disposed on the +Y side of the substrate stagePST, that emits a plurality of detection beams La arrayed in the X axialdirection; a first light receiving portion 62X, which is disposed on the−Y side of the substrate stage PST at a prescribed position with respectto the detection beams La emitted from the first light emitting portion61X; a second light emitting portion 61Y, which is disposed on the −Xside of the substrate stage PST, that emits a plurality of detectionbeams La arrayed in the Y axial direction; and a second light receivingportion 62Y, which is disposed on the +X side of the substrate stage PSTat a prescribed position with respect to the detection beams La emittedfrom the second light emitting portion 61Y. The first light receivingportion 62X has a plurality of light receiving devices corresponding tothe plurality of detection beams La emitted from the first lightemitting portion 61X; likewise, the second light receiving portion 62Yhas a plurality of light receiving devices corresponding to theplurality of detection beams La emitted from the second light emittingportion 61Y.

The detection beams La emitted from the first light emitting portion 61Xand the detection beams La emitted from the second light emittingportion 61Y are each emitted substantially parallel to the front surfaceof the substrate P and the upper surface 43 of the substrate stage PST,and the optical paths of these detection beams La are provided in amatrix configuration in a plan view.

Here, as depicted in FIG. 5, if the liquid LQ is present in the opticalpath of a specific detection beam Lax among the plurality of detectionbeams La emitted from the first light emitting portion 61X, then thelight quantity received by the light receiving device, which correspondsto that detection beam Lax among the plurality of light receivingdevices of the first light receiving portion 62X, will decrease.Likewise, if the liquid LQ is present in the optical path of a specificdetection beam Lay among the plurality of detection beams La emittedfrom the second light emitting portion 61Y, then the light quantityreceived by the light receiving device, which corresponds to thatdetection beam Lay among the plurality of light receiving devices of thesecond light receiving portion 62Y, will decrease. The light receivingresults of the first and second light receiving portions 62X, 62Y areoutputted to the control apparatus CONT. Based on these light receivingresults from the first and second light receiving portions 62X, 62Y, thecontrol apparatus CONT can specify that the position of the liquid LQ isin the vicinity of the intersection of the detection beam Lax and thedetection beam Lay. At this point, because the positional information ofthe light receiving devices that receive the detection beams Lax, Lay isknown in advance based on design values and the like, the controlapparatus CONT can derive, based on the positional information of thelight receiving devices that received the detection beams Lax, Lay, theposition of the liquid LQ on the substrate P or on the substrate stagePST.

In addition, as depicted in FIG. 6, the detection apparatus 60 canderive, based on the light receiving results of the light receivingportion 62 produced when the detection beams La were emitted from thelight emitting portion 61 to each of a plurality of positions, the sizeof the liquid LQ (the size of the area in which the liquid LQ isdisposed) present on the substrate P and on the substrate stage PST. Inother words, if the liquid LQ is disposed in a prescribed area on thesubstrate stage PST (or on the substrate P), then the light emittingportion 61 emits the detection beams La to a plurality of positions thatincludes an edge portion LG of the liquid LQ. In the example depicted inFIG. 6, the light emitting portion 61 emits the plurality of detectionbeams La, which are arrayed in the Y axial direction, along the X axialdirection.

The light receiving portion 62 has a plurality of light receivingdevices corresponding to the plurality of detection beams La. Thepositional information of these light receiving devices is known inadvance by, for example, design values. If the liquid LQ is irradiatedby some of the plurality of detection beams La emitted from the lightemitting portion 61, i.e., detection beams La1, then the detection beamsLa1 do not arrive at the light receiving devices of the light receivingportion 62 corresponding to those detection beams La1, or the lightquantities received by those light receiving devices decrease. On theother hand, the remaining detection beams La, i.e., detection beams La2,arrive at the light receiving portion 62 without passing through theliquid LQ. Accordingly, the detection apparatus 60 can derive, based onthe light receiving results of the light receiving devices of the lightreceiving portion 62 that received the detection beams La1 and based onthe positional information of those light receiving devices, the size ofthe liquid LQ (the area in which the liquid LQ is disposed).

Furthermore, in the example depicted in FIG. 6, the detection apparatus60 irradiates the liquid LQ with the detection beams La from the X axialdirection, and consequently the size of the liquid LQ (the area in whichthe liquid LQ is disposed) in the Y axial direction can be derived;furthermore, by irradiating the liquid LQ with the detection beams Lafrom the Y axial direction, the size of the liquid LQ in the X axialdirection can be derived. In addition, it is also possible, of course,to emit the detection beams La within the XY plane from a directiondiagonal to the X axis (as well as the Y axis) direction. Furthermore,by arithmetically processing the light receiving results produced whenthe liquid LQ was irradiated with the detection beams La from aplurality of directions, the detection apparatus 60 (or the controlapparatus CONT) can derive the shape of the liquid LQ (the area in whichthe liquid LQ is disposed).

Furthermore, in the example explained referencing FIG. 6, the lightemitting portion 61 emits the plurality of detection beams La all atonce; however, as was explained referencing, for example, FIG. 3, it isalso possible to emit one detection beam La (or a prescribed pluralitythereof) from the light emitting portion 61 while moving the substratestage PST as well as while monitoring the position thereof using thelaser interferometer 46, and to derive the size or shape of the liquidLQ based on the light receiving result of the light receiving portion 62produced when that detection beam La was emitted. In that case, thedetection apparatus 60 (or the control apparatus CONT) derives at leastthe size or the shape of the liquid LQ by arithmetically processing theplurality of light receiving results of the light receiving portion 62corresponding to a plurality of positions of the substrate stage PST.

In addition, in the example explained referencing FIG. 6, the lightemitting portion 61 emits a plurality of arrayed detection beams La, butit may emit a sheet light beam that covers the liquid LQ. A so-calledlaser sheet light generated by, for example, passing the laser lightbeam emitted from a laser light source through an optical system thathas a pinhole or a cylindrical lens, can be used as the sheet lightbeam.

The following explains a method of using the exposure apparatus EX thathas the constitution discussed above to expose the substrate P with thepattern image of the mask M, referencing the flowchart diagram depictedin FIG. 7.

First, the mask M is loaded on the mask stage MST and the substrate P,which is the exposure target, is loaded on the substrate stage PST (stepS1).

When loading the substrate P on the substrate stage PST, the controlapparatus CONT moves the substrate stage PST to a load position, whichis set to a position away from the projection optical system PL. Thesubstrate P is loaded at the load position by a conveyor system (loadingapparatus), which is not shown.

After the substrate P is loaded on the substrate stage PST, thealignment process and the measurement process are performed on thesubstrate P (step S2).

In the alignment process, the control apparatus CONT uses, for example,the abovementioned substrate alignment system to detect the fiducialmark PFM formed on the fiducial member 300, and uses the mask alignmentsystem to detect, through the projection optical system PL, the fiducialmark MFM formed on the fiducial member 300; thereby, the controlapparatus CONT derives a baseline quantity that is the distance(positional relationship) between a detection reference position of thesubstrate alignment system within the coordinate system that stipulatesthe movement of the substrate stage PST, and the projection position ofthe pattern image of the mask M. When detecting the fiducial mark MFM onthe fiducial member 300 using the mask alignment system, the controlapparatus CONT supplies and recovers the liquid LQ using the liquidsupply mechanism 10 and the liquid recovery mechanism 20 in a statewherein the projection optical system PL and the upper surface 301A ofthe fiducial member 300 oppose one another, thereby forming theimmersion area AR2 of the liquid LQ between the optical element 2 at thefront end portion of the projection optical system PL and the uppersurface 301A of the fiducial member 300. Furthermore, the controlapparatus CONT detects, through the projection optical system PL and theliquid LQ, the fiducial mark MFM on the fiducial member 300 using themask alignment system.

After the detection of the fiducial mark MFM has finished, the controlapparatus CONT uses the liquid recovery mechanism 20 or a prescribedliquid recovery mechanism provided separately therefrom to collect theliquid LQ in the immersion area AR2 formed on the upper surface 301A ofthe fiducial member 300.

When superimposingly exposing the substrate P, the projection positionof the pattern image of the mask M can be aligned with a shot region byusing the substrate alignment system to detect the alignment mark formedon that shot region, which is, for example, the exposure target area onthe substrate P, deriving the positional information (deviation) of theshot region with respect to the detection reference position of thesubstrate alignment system, and then moving the substrate stage PST bythe sum of the above-described baseline quantity and the deviation ofthe shot region that was derived by the substrate alignment system, fromthe current substrate stage PST position.

In addition, in the measurement process, the control apparatus CONTforms the immersion area AR2 of the liquid LQ between the opticalelement 2 at the front end portion of the projection optical system PLand the upper surface 401A of the upper plate 401 by supplying andrecovering the liquid LQ using the liquid supply mechanism 10 and theliquid recovery mechanism 20 in a state wherein, for example, theprojection optical system PL and the upper plate 401 of the luminousflux intensity nonuniformity sensor 400 are disposed so that they opposeone another. Furthermore, the control apparatus CONT emits the exposurelight EL from the illumination optical system IL and detects, throughthe projection optical system PL and the liquid LQ, the luminous fluxintensity distribution of the exposure light EL in the projection areaAR1 by the luminous flux intensity nonuniformity sensor 400. The controlapparatus CONT appropriately corrects the radiation distribution of theexposure light EL based on the detection result of the luminous fluxintensity nonuniformity sensor 400 so that the luminous flux intensitydistribution of the exposure light EL in the projection area AR1 of theprojection optical system PL reaches a desired state.

After the detection of the luminous flux intensity distribution of theexposure light EL is finished, the control apparatus CONT uses theliquid recovery mechanism 20, or a prescribed liquid recovery mechanismprovided separately therefrom, to collect the liquid LQ in the immersionarea AR2 formed on the upper surface 401A of the upper plate 401 of theluminous flux intensity nonuniformity sensor 400.

In addition, the control apparatus CONT, in a state wherein theprojection optical system PL and the upper plate 501 of the spatialimage measuring sensor 500 are disposed so that they oppose one another,uses the liquid supply mechanism 10 and the liquid recovery mechanism 20to supply and recover the liquid LQ so as to form the immersion area AR2of the liquid LQ between the optical element 2 at the front end portionof the projection optical system PL and the upper surface 501A of theupper plate 501. Furthermore, the control apparatus CONT emits theexposure light EL from the illumination optical system IL and measures,through the projection optical system PL and the liquid LQ, the spatialimage using the spatial image measuring sensor 500. Based on themeasurement result of the spatial image measuring sensor 500, thecontrol apparatus CONT appropriately corrects the image characteristicsof the projection optical system PL so that the characteristics of theimage formed through the projection optical system PL and the liquid LQreach the desired state.

After the spatial image measurement is finished, the control apparatusCONT uses the liquid recovery mechanism 20, or a prescribed liquidrecovery mechanism provided separately therefrom, to collect the liquidLQ in the immersion area AR2 formed on the upper surface 501A of theupper plate 501 of the spatial image measuring sensor 500.

Similarly, the control apparatus CONT, in a state wherein the immersionarea AR2 of the liquid LQ is formed between the projection opticalsystem PL and the luminous flux intensity sensor (not shown) discussedabove, measures the amount of radiation of the exposure light EL (theluminous flux intensity) on the image plane side of the projectionoptical system PL and, based on that measurement result, appropriatelycorrects the luminous flux intensity of the exposure light EL.Furthermore, after the measurement process that uses the luminous fluxintensity sensor is finished, the control apparatus CONT uses the liquidrecovery mechanism 20 and the like to collect the liquid LQ on the upperplate of the luminous flux intensity sensor.

Incidentally, after the measurement process through the liquid LQ using,for example, the abovementioned fiducial member 300, the luminous fluxintensity nonuniformity sensor 400, the spatial image measuring sensor500, or the luminous flux intensity sensor, is finished and the liquidLQ is recovered, there is a possibility that the liquid LQ will remainon (adhere to) the upper surface 301A of the fiducial member 300 and thelike. Therefore, after performing the work of recovering the liquid LQ,the control apparatus CONT uses the detection apparatus 60 to detectwhether the liquid LQ is present on the substrate stage PST, includingthe abovementioned upper surfaces 301A, 401A, 501A, and the like.

For example, after the liquid LQ on the upper surface 301A of thefiducial member 300 is collected, the control apparatus CONT uses thedetection apparatus 60 to detect whether the liquid LQ is present on thefiducial member 300. Based on the detection results of the detectionapparatus 60, the control apparatus CONT controls the operation of theliquid recovery mechanism 20. Specifically, if it is determined that theliquid LQ is present on the fiducial member 300, then the controlapparatus CONT uses the liquid recovery mechanism 20 and the like toonce again perform the operation of collecting the liquid LQ present onthe fiducial member 300. Subsequently, the control apparatus CONT usesthe detection apparatus 60 to once again detect whether the liquid LQ ispresent on the fiducial member 300. Furthermore, the control apparatusCONT repetitively performs the detection operation using the detectionapparatus 60 and the liquid recovery operation by the liquid recoverymechanism 20 until the liquid LQ is no longer detected by the detectionapparatus 60. Alternatively, the control apparatus CONT can perform theliquid detection operation by using the detection apparatus 60 and theliquid recovery operation by the liquid recovery mechanism 20 inparallel.

In this case, the control apparatus CONT continues the liquid recoveryoperation by the liquid recovery mechanism 20 until the detectionapparatus 60 no longer detects the liquid LQ. This avoids the problemwherein the liquid LQ remains on the substrate stage PST, including onthe fiducial member 300, after the process of performing the measurementthrough the liquid LQ is finished. However, if it is determined based onthe detection results of the detection apparatus 60 that the recovery ofthe liquid LQ was completed by a single liquid recovery procedure, thenthe detection apparatus 60 does not need to perform detection again.

In addition, when the immersion area AR2 of the liquid LQ has beenformed on the upper surface 301A of the fiducial member 300, there is apossibility that the liquid LQ will scatter or flow out to thesurroundings of the immersion area AR2. Accordingly, the controlapparatus CONT uses the detection apparatus 60 to detect whether theliquid LQ is present on, for example, the upper surface 43 of thesubstrate stage PST as well as on the fiducial member 300. In addition,if it is determined that the liquid LQ is present on the upper surface43 of the substrate stage PST, then the control apparatus CONT uses theliquid recovery mechanism 20 to collect the liquid LQ present on theupper surface 43.

Therefore, as discussed above, the detection apparatus 60 can derive thepositional information of the liquid LQ present on the substrate stagePST (the fiducial member 300). Accordingly, the control apparatus CONTcan perform the liquid recovery operation in a state wherein the liquidrecovery ports 22 of the liquid recovery mechanism 20 are aligned withthe position where the liquid LQ is present by moving the substratestage PST based on the positional information of the liquid LQ. Thereby,it is possible to improve the throughput of the liquid recoveryoperation. Of course, the liquid may be recovered while moving thesubstrate stage PST with respect to the liquid recovery ports 22 so thatthe entire area of the upper surface 43 of the substrate stage PSTpasses below the liquid recovery ports 22.

In addition, as discussed above, the detection apparatus 60 can deriveinformation related to the size of the liquid LQ on the substrate stagePST (the fiducial member 300), as well as to the amount of the liquidLQ. Accordingly, based on the information related to the size (amount)of the liquid LQ, the control apparatus CONT can control the recovery(i.e., collecting) force (suction force) of the liquid recoverymechanism 20 or the recovery time (suction time) thereof. For example,if the size of the liquid LQ is large (if the amount is great), then thecontrol apparatus CONT increases the recovery force of the liquidrecovery mechanism 20, or lengthens the recovery time.

Thereby, the liquid LQ is satisfactorily recovered. On the other hand,if the size of the liquid LQ is small (if the amount is small), then thecontrol apparatus CONT reduces the recovery force of the liquid recoverymechanism 20, or shortens the recovery time. The throughput of theliquid recovery operation is thereby improved.

In addition, if it is determined based on the detection results of thedetection apparatus 60 that the amount of the liquid LQ present on thefiducial member 300 (on the substrate stage PST) is less than a presetthreshold value, or if it is determined that the liquid LQ is present ata position (on an object) that has little impact on the measurementprocess or the exposure process, then the control apparatus CONT canomit performing the operation of recovering the liquid LQ using theliquid recovery mechanism 20, even if the liquid LQ is present.

In addition, it is also possible to perform the detection operation byusing the detection apparatus 60 in parallel with the measurementoperation in a state wherein the immersion area AR2 of the liquid LQ isformed on the upper surface 301A of the fiducial member 300. Forexample, the detection apparatus 60 emits the detection beams La betweenthe upper surface 301A and the optical element 2 of the projectionoptical system PL during the measurement operation in a state whereinthe immersion area AR2 of the liquid LQ is formed on the upper surface301A. It is thereby possible to detect whether a gap between the opticalelement 2 of the projection optical system PL and the upper surface 301Aof the fiducial member 300 is filled with the liquid LQ. Furthermore, ifit is determined that the gap is not filled with the liquid LQ, then thecontrol apparatus CONT takes appropriate measures, such as, for example,stopping the measurement operation that uses the fiducial member 300, ormodifying, for example, the liquid supply condition of the liquid supplymechanism 10 or the liquid recovery condition of the liquid recoverymechanism 20 so as to fill the gap with the liquid LQ.

In addition, the detection beams La may be made to pass the outer sideof the immersion area AR2 of the liquid LQ formed on the upper surface301A of the fiducial member 300, and the measurement operation may beperformed using the fiducial member 300.

Thereby, if an abnormality occurs such as, for example, the outflow ofthe liquid LQ from the upper surface 301A of the fiducial member 300,then the detection apparatus 60 can detect that outflow of the liquidLQ. If it has been determined based on the detection results of thedetection apparatus 60 that an abnormality has occurred, such as theoutflow of the liquid LQ, then the control apparatus CONT, for example,reduces the amount of the liquid supplied per unit of time by the liquidsupply mechanism 10, or stops the supply of the liquid LQ by the liquidsupply mechanism 10. If the supply of the liquid LQ by the liquid supplymechanism 10 is stopped, then the drive of the liquid supply portion 11may be stopped, or the passageways of the supply pipes 13A, 13B may beclosed using the valves. Alternatively, the control apparatus CONT mayincrease the amount of the liquid recovered per unit of time by theliquid recovery mechanism 20, or stop the movement of the substratestage PST.

As described above, the operation of the liquid supply mechanism 10, theliquid recovery mechanism 20, and the like can be controlled based onthe detection results of the detection apparatus 60, and the immersionarea AR2 can thereby be satisfactorily formed. In addition, even if anabnormality occurs, such as the outflow of the liquid LQ, it is possibleto suppress an extension of the damage by taking appropriate measures,such as stopping the supply of the liquid LQ by the liquid supplymechanism 10.

Furthermore, the detection operation using the detection apparatus 60,of course, can be performed after, in parallel with, or before themeasurement process that uses the fiducial member 300. For example,prior to performing the measurement process, it is possible to first usethe detection apparatus 60 to detect whether the immersion area AR2 issatisfactorily formed between the projection optical system PL and thefiducial member 300, and then to perform the measurement process.

Furthermore, the explanation herein was made taking as an example a casewherein the immersion area AR2 of the liquid LQ is formed on the uppersurface 301A of the fiducial member 300, the measurement process isperformed, and the liquid is recovered, after which the detectionapparatus 60 is used to detect the liquid LQ on the substrate stage PST,including on the upper surface 301A; however, it is also possible (i) toform the immersion area of the liquid LQ on the upper surface 401A ofthe upper plate 401 of the luminous flux intensity nonuniformity sensor400, perform the measurement process, and collect the liquid LQ on thatupper surface 401A, (ii) to form the immersion area of the liquid LQ onthe upper surface 501A of the upper plate 501 of the spatial imagemeasuring sensor 500, perform the measurement process, and collect theliquid LQ on the upper surface 501A, or (iii) to form the immersion areaof the liquid LQ on the upper surface of the upper plate of the luminousflux intensity sensor, perform the measurement process, and collect theliquid LQ on that upper surface; and then use the detection apparatus 60to detect whether the liquid LQ is present on those upper plates or thesubstrate stage PST. Furthermore, based on the detection results of thedetection apparatus 60, the control apparatus CONT can control theoperation of the liquid supply mechanism 10, the liquid recoverymechanism 20, and the like. Furthermore, it is also possible to performthe detection operation using the detection apparatus 60 in parallelwith or before the measurement operation using the luminous fluxintensity nonuniformity sensor 400, the spatial image measuring sensor500, and the like.

After the abovementioned alignment process, measurement process, and thelike are finished and prior to performing the scanning exposure processof the substrate P, the control apparatus CONT disposes the projectionoptical system PL and the substrate P so that they oppose one another.Furthermore, the control apparatus CONT supplies the liquid LQ to thesubstrate P by driving the liquid supply mechanism 10, and collects aprescribed amount of the liquid LQ on the substrate P by driving theliquid recovery mechanism 20. Thereby, the immersion area AR2 of theliquid LQ is formed between the substrate P and the optical element 2 atthe front end portion of the projection optical system PL (step S3).

Furthermore, after the alignment process and the measurement process(step S2) are finished, the method may transition to the operation ofthe immersion exposure process of the substrate P while holding theliquid LQ on the image plane side of the projection optical system PLwithout recovering the liquid LQ.

The control apparatus CONT projects the pattern image of the mask M ontothe substrate P via the projection optical system PL and the liquid LQbetween the projection optical system PL and the substrate P so as toexpose the substrate P while moving the substrate stage PST, whichsupports the substrate P, in the X axial direction (the scanningdirection), and while the liquid supply mechanism 10 supplies the liquidLQ onto the substrate P and, in parallel, the liquid recovery mechanism20 collects the liquid LQ on the substrate P (Step 4).

After the liquid LQ supplied from the liquid supply portion 11 of theliquid supply mechanism 10 to form the immersion area AR2 is distributedthrough the supply pipes 13A, 13B, it is supplied onto the substrate Pby the liquid supply ports 12A, 12B through the supply passagewaysformed inside the passageway forming member 70. The liquid LQ suppliedonto the substrate P from the liquid supply ports 12A, 12B is suppliedso that it spreads between the substrate P and the lower end surface ofthe front end portion (the optical element 2) of the projection opticalsystem PL, and locally forms the immersion area AR2, which is smallerthan the substrate P and larger than the projection area AR1, on aportion of the substrate P that includes the projection area AR1. Atthis time, the control apparatus CONT simultaneously supplies the liquidLQ onto the substrate P from both sides of the projection area AR1 inthe scanning directions by the liquid supply ports 12A, 12B of theliquid supply mechanism 10 disposed on both sides in the X axialdirection (the scanning directions) of the projection area AR1. Thereby,the immersion area AR2 is uniformly and satisfactorily formed.

The exposure apparatus EX in the present embodiment exposes thesubstrate P by projecting the pattern image of the mask M onto thesubstrate, while moving the mask M and the substrate P in the X axialdirection (the scanning direction); during scanning exposure, thepattern image of one portion of the mask M is projected inside theprojection area AR1 through the projection optical system PL and theliquid LQ of the immersion area AR2, and, synchronized to the movementof the mask M at a velocity V in the −X direction (or the +X direction),the substrate P moves at a speed β·V (where β is the projectionmagnification) in the +X direction (or the −X direction) with respect tothe projection area AR1. Furthermore, a plurality of shot regions areset on the substrate P; after the exposure of one shot region isfinished, the next shot region moves to the scanning start position bythe stepping movement of the substrate P, and the scanning exposureprocess is subsequently performed sequentially for each shot regionwhile moving the substrate P by the step-and-scan system.

Furthermore, in the present embodiment, when supplying the liquid LQ tothe substrate P from both sides of the projection area AR1 in thescanning directions, the control apparatus CONT uses the flowcontrollers 16A, 16B of the liquid supply mechanism 10 to adjust theamount of the liquid supplied per unit of time so that, during thescanning exposure of one shot region on the substrate P, the amount ofliquid (supplied per unit of time) supplied from one side of theprojection area AR1 in the scanning direction differs from the amount ofliquid supplied from the other side. Specifically, the control apparatusCONT sets the amount of liquid supplied per unit of time from the nearside of the projection area AR1 in the scanning direction so that it isgreater than the amount of liquid supplied from the opposite side; forexample, if performing an exposure process while moving the substrate Pin the +X direction, then the control apparatus CONT sets the amount ofliquid supplied from the −X side (i.e., the liquid supply port 12A) tothe projection area AR1 so that it is greater than the amount of liquidsupplied from the +X side (i.e., the liquid supply port 12B); on theother hand, if the exposure process is performed while moving thesubstrate P in the −X direction, then the amount of liquid supplied fromthe +X side to the projection area AR1 is set so that it is greater thanthe amount of liquid supplied from the −X side. Thus, the controlapparatus CONT varies the amount of liquid supplied per unit of timefrom each of the liquid supply ports 12A, 12B in accordance with themovement direction of the substrate P.

Furthermore, the operation of the immersion exposure process of thesubstrate P can be performed in parallel with the detection operation ofthe detection apparatus 60. For example, during the measurementoperation in a state wherein the immersion area AR2 of the liquid LQ isformed on the substrate P, the detection apparatus 60 emits thedetection beams La between the substrate P and the optical element 2 ofthe projection optical system PL. Thereby, it is possible to detectwhether the gap between the substrate P and the optical element 2 of theprojection optical system PL is filled with the liquid LQ. Furthermore,if it is determined that the gap is not filled with the liquid LQ, thenthe control apparatus CONT takes appropriate measures, such as, forexample: stopping the immersion exposure operation; or, in order to fillthe gap with the liquid LQ, modifying, for example, the conditions inwhich the liquid is supplied by the liquid supply mechanism 10 or theconditions in which the liquid is recovered by the liquid recoverymechanism 20. Thereby, the exposure process can be performed in a statewherein the immersion area AR2 is satisfactorily formed.

In addition, the immersion exposure process may be performed on thesubstrate P in a state wherein the detection beams La are emitted to theouter side of the immersion area AR2 of the liquid LQ formed on thesubstrate P. Thereby, if, for example, an abnormality arises such as theoutflow of the liquid LQ from the immersion area AR2 formed on thesubstrate P, then the detection apparatus 60 can detect that outflow ofthe liquid LQ. If it is determined based on the detection results of thedetection apparatus 60 that an abnormality has occurred, such as theoutflow of the liquid LQ, then the control apparatus CONT, for example,reduces the amount of liquid supplied per unit of time by the liquidsupply mechanism 10, or stops the supply of the liquid LQ by the liquidsupply mechanism 10. If the supply of the liquid LQ by the liquid supplymechanism 10 is stopped, then the drive of the liquid supply portion 11may be stopped, or the passageways of the supply pipes 13A, 13B may beclosed using the valves. Alternatively, based on the detection resultsof the detection apparatus 60, the control apparatus CONT may increasethe amount of liquid recovered per unit of time by the liquid recoverymechanism 20. Alternatively, based on the detection results of thedetection apparatus 60, the control apparatus CONT may stop theoperation of exposing the substrate P, the movement of the substratestage PST, and the like.

Furthermore, it is also possible to perform the detection operationusing the detection apparatus 60 before the immersion exposure of thesubstrate P, or before supplying the liquid LQ thereto. For example,prior to performing the immersion exposure, it is possible to first usethe substrate alignment system to detect the alignment mark on thesubstrate P after the detection apparatus 60 confirms that there is noliquid LQ on the substrate P, or to use the detection apparatus 60 todetect whether the immersion area AR2 of the liquid LQ is satisfactorilyformed between the projection optical system PL and the substrate P, andthen to perform the immersion exposure process.

After the immersion exposure of the substrate P is finished, the controlapparatus CONT collects the liquid LQ of the immersion area AR2 formedon the substrate P using the liquid recovery mechanism 20, or aprescribed liquid recovery mechanism provided separately therefrom. Inaddition, there is also a possibility that the liquid LQ of theimmersion area AR2 formed on the substrate P will scatter or flow out tothe surroundings. Therefore, the control apparatus CONT uses the liquidrecovery mechanism 20, or a prescribed liquid recovery mechanismprovided separately therefrom, to collect, in addition to the liquid LQremaining on the substrate P, the liquid LQ remaining on, for example,the fiducial member 300 or the upper surface 43 of the substrate stagePST, including on the upper plates 401, 501 (step S5).

After the liquid LQ on the substrate stage PST, including on thesubstrate P, is collected, the control apparatus CONT uses the detectionapparatus 60 to detect whether the liquid LQ is present on the substrateP, the substrate stage PST, and the like. Based on the detection resultsof the detection apparatus 60, the control apparatus CONT controls theoperation of the liquid recovery mechanism 20. Specifically, if it isdetermined that the liquid LQ is present on the substrate P or thesubstrate stage PST, then the control apparatus CONT uses the liquidrecovery mechanism 20 and the like to once again perform the operationof collecting the liquid LQ present on the substrate P or the substratestage PST. Subsequently, the control apparatus CONT uses the detectionapparatus 60 to once again detect whether the liquid LQ is present onthe substrate P or the substrate stage PST. Furthermore, the controlapparatus CONT repetitively performs the detection operation using thedetection apparatus 60 and the liquid recovery operation by the liquidrecovery mechanism 20 until the liquid LQ is no longer detected by thedetection apparatus 60. Alternatively, the control apparatus CONT canperform the liquid detection operation by using the detection apparatus60 and the liquid recovery operation by the liquid recovery mechanism 20in parallel. In this case, the control apparatus CONT continues theliquid recovery operation by the liquid recovery mechanism 20 until thedetection apparatus 60 no longer detects the liquid LQ. This avoids theproblem wherein the liquid LQ remains on the substrate P, the substratestage PST, and the like after the immersion exposure. However, if it isdetermined based on the detection results of the detection apparatus 60that the recovery of the liquid LQ was completed by a single liquidrecovery procedure, then the detection apparatus 60 does not need toperform detection again.

The detection apparatus 60 can derive the positional information of theliquid LQ present on the substrate P or the substrate stage PST, and thecontrol apparatus CONT can therefore perform the liquid recoveryoperation in a state wherein the liquid recovery ports 22 of the liquidrecovery mechanism 20 are aligned with the position where the liquid LQis present by moving the substrate stage PST based on the positionalinformation of the liquid LQ. Thereby, it is possible to improve thethroughput of the liquid recovery operation. Of course, the liquid maybe collected while moving the substrate stage PST, including the frontsurface of the substrate P, with respect to the liquid recovery port 22so that the entire area of the upper surface 43 of the substrate stagePST passes below the liquid recovery port 22.

In addition, as discussed above, the detection apparatus 60 can deriveinformation related to the size of the liquid LQ on the substrate stagePST, including on the front surface of the substrate P, as well as tothe amount of the liquid LQ. Accordingly, based on the informationrelated to the size (amount) of the liquid LQ, the control apparatusCONT can control the recovery force (suction force) of the liquidrecovery mechanism 20 or the recovery time (suction time) thereof. Forexample, if the size of the liquid LQ is large (if the amount is great),then the control apparatus CONT increases the recovery force of theliquid recovery mechanism 20, or lengthens the recovery time. Thereby,the liquid LQ is satisfactorily recovered. On the other hand, if thesize of the liquid LQ is small (if the amount is small), then thecontrol apparatus CONT reduces the recovery force of the liquid recoverymechanism 20, or shortens the recovery time. The throughput of theliquid recovery operation is thereby improved.

In addition, if it is determined based on the detection results of thedetection apparatus 60 that the amount of the liquid LQ present on thesubstrate stage PST, including on the front surface of the substrate P,is less than a preset threshold value, or if it is determined that theliquid LQ is present at a position (on an object) that has little impacton the measurement process or the exposure process, then the controlapparatus CONT can omit performing the operation of recovering theliquid LQ using the liquid recovery mechanism 20, even if the liquid LQis present.

After collecting the liquid LQ on the substrate P and on the substratestage PST, the control apparatus CONT unloads the substrate P for whichthe exposure has finished from the substrate stage PST (step S6).

When unloading the substrate P from the substrate stage PST, the controlapparatus CONT moves the substrate stage PST to an unload position,which is set to a position away from the projection optical system PL.The conveyor system (unloading apparatus), which is not shown, unloadsthe substrate P at the unload position. Furthermore, the load positionand the unload position may be the same position or they may bedifferent.

Furthermore, in the present embodiment, the detection apparatus 60detects whether the liquid LQ is present on the substrate stage PST,including on the front surface of the substrate P; however, thedetection apparatus 60 can also detect whether the liquid LQ is presenton, for example, the linear motors 47, 48, the surface of the X guidestage 44 wherein the stator 47A of the linear motor 47 is provided, theair bearings 42, 51, 52, or the side surface of the substrate stage PST,which are all disposed lower than the front end portion of theprojection optical system PL. There is a possibility that the liquid LQof the immersion area AR2 formed on the substrate P and on the substratestage PST will scatter or flow out and adhere to the abovementionedlinear motors and air bearings, or to the surface of the X guide stage44. If the liquid LQ adheres to, for example, the linear motor 47(stator 47A) of the X guide stage 44, then problems, such as electricalleakage, will occur. Alternatively, if the liquid LQ adheres to thevicinity of the air bearings 42, then a problem will occur wherein theliquid LQ will flow into the intake ports 42A of the air bearings 42.Alternatively, if the liquid LQ that adheres to the side surface of thesubstrate stage PST and the like is left as is, then there is also apossibility that the liquid LQ will cause rusting, or will vaporize andcause fluctuations in the environment wherein the substrate P isdisposed. Accordingly, the control apparatus CONT uses the detectionapparatus 60 to detect that adhered liquid LQ. Because it is abnormal ifthe liquid LQ adheres at a position (a member) outside of the desiredposition, such as to the X guide stage 44, if the control apparatus CONTdetermines that the detection results of the detection apparatus 60 areabnormal, then it can prevent the occurrence of the abovementionedproblems by removing that liquid LQ using a prescribed liquid removalmechanism and the like.

In addition, if the presence of the liquid LQ is detected in thevicinity of electrical equipment, including the abovementioned linearmotors (electromagnetic drive sources), then it is also possible thatthe control apparatus CONT determines that the detection results of thedetection apparatus 60 are abnormal and, for example, stops the supplyof electrical power to the electrical equipment. In so doing, it ispossible to prevent the occurrence of electrical leakage.

In addition, if the presence of the liquid LQ is detected in, forexample, the vicinity of the intake ports 42A of the air bearings 42,then it is possible that the control apparatus CONT stops the intakeoperation from the intake ports 42A.

In addition, if it is determined that the detection results of thedetection apparatus 60 are abnormal, such as the adherence of the liquidLQ to the X guide stage 44 and the like, then the control apparatus CONTcan also issue a warning by driving the warning apparatus K. Thereby,the operator, for example, can ascertain that an abnormality, such asthe leakage of the liquid LQ, has occurred inside the exposure apparatusEX, and can therefore take appropriate measures. The warning apparatus Kcan issue a warning using a warning lamp, a warning sound, a display,and the like. Furthermore, if the detection results of the detectionapparatus 60 are determined to be abnormal, then it is also possible toinform the operator that an abnormality has occurred via, for example, acomputer network.

In addition, if the detection apparatus 60 detects an abnormality, suchas the presence of a large amount of the liquid LQ on the X guide stage44 or the side surface of the substrate stage PST, for example, duringan immersion exposure of the substrate P or during the measurementprocess in a state wherein the immersion area AR2 is formed on thefiducial member 300, the upper plates 401, 501, and the like, then thecontrol apparatus CONT determines that an abnormality has occurred, suchas the outflow of the liquid LQ from the immersion area AR2 on thesubstrate stage PST. If it is determined that the detection results ofthe detection apparatus 60 are abnormal, then the control apparatus CONTmay stop the supply of the liquid LQ by the liquid supply mechanism 10.Thereby, it is possible to prevent problems, such as electrical leakage,the scattering of the liquid LQ that flowed out, or the inflow of theliquid LQ into the intake ports 42A. In addition, even in this case, ifit is determined that the detection results of the detection apparatus60 are abnormal, then the control apparatus CONT may stop the exposureoperation.

As explained above, the detection apparatus 60 can be used to detectwhether the liquid LQ is present at a desired position or a positionoutside of the desired position, such as: on the substrate P, thesubstrate stage PST, or the X guide stage 44, which are disposed lowerthan the front end portion of the projection optical system PL.Accordingly, if the liquid LQ is disposed at, for example, a positionoutside of the desired position, then it is possible, based on thedetection results of the detection apparatus 60, to take appropriatemeasures, such as controlling the operation of the liquid supplymechanism 10, the liquid recovery mechanism 20, and the like, as well asremoving that liquid LQ; therefore, even if an abnormality, such as theoutflow of the liquid LQ, occurs, it is possible to suppress the damagefrom extending further.

Furthermore, in the present embodiment discussed above, the lightemitting portion 61 and the light receiving portion 62 of the detectionapparatus 60 are provided to the outer side (the main column 3) of thesubstrate stage PST, but it is also possible to provide at least one ofthe light emitting portion 61 and the light receiving portion 62 of thedetection apparatus 60 on the substrate stage PST. On the other hand, byadopting a constitution as in the embodiment discussed above, whereinthe light emitting portion 61 and the light receiving portion 62 of thedetection apparatus 60 are provided to the outer side of the substratestage PST and optically (contactlessly) detect the liquid LQ from theouter side of the substrate stage PST, there is no need to dispose, forexample, the detection devices, the wiring that connects those detectiondevices, and various members (equipment) in order to detect the liquidLQ on the substrate stage PST. Consequently, it is possible to reducethe impact on the movement of the substrate stage PST.

Furthermore, while it is also possible to use visible light and the likefor the detection beams La, it is preferable to use infrared light of aprescribed wavelength (a prescribed wavelength band). Specifically, itis preferable to use infrared light of a wavelength of, for example,approximately 1200 nm, 1450 nm, 1940 nm, or 2950 nm for the detectionbeams La. Because the water (liquid) LQ has a physical property thatabsorbs light of the above wavelengths (infrared light), if thedetection beams (infrared beams) La that have any of the abovewavelengths are emitted to the liquid LQ, then the light energy of thosedetection beams La is absorbed by the water (liquid) LQ, which greatlydecreases the amount of light received by the light receiving portion62. Accordingly, there is an increased difference between the amount oflight received by the light receiving portion 62 when the detectionbeams La are emitted to the liquid LQ and the amount of light receivedby the light receiving portion 62 when the detection beams La are notemitted to the liquid LQ, and the detection apparatus 60 canconsequently detect with greater sensitivity whether the liquid LQ ispresent.

In addition, the use of infrared light for the detection beams Lagreatly increases the difference for example, between the amount oflight received by the light receiving portion 62 when the detectionbeams La are emitted to foreign matter (particles) adhering on thesubstrate P and the amount of light received by the light receivingportion 62 when the detection beams La are emitted to the liquid LQ;thus, the detection apparatus 60 can discriminate particles from theliquid LQ. Furthermore, if it is determined that the liquid LQ ispresent, then the liquid LQ should be recovered using the liquidrecovery mechanism 20 and the like; further, if it is determined thatparticles are present, then those particles should be removed using aprescribed particle removal mechanism.

In addition, when detecting whether the liquid LQ is present on theupper surface 43 of the substrate stage PST, the upper surface of thesubstrate holder PH, and the like, even if a member exists that, forexample, protrudes slightly from the upper surface of the substrateholder PH (e.g., a pin member that constitutes portion of a holdingmechanism (a pin chuck mechanism) that holds the substrate P), the useof infrared light for the detection beams La also enables the detectionapparatus 60 to discriminate the liquid LQ from that protruding member.Accordingly, because it is possible to avoid the occurrence of a problemwherein it is mistakenly determined that the protruding member is theliquid LQ, it is possible to avoid the occurrence of the problem whereinthroughput is unfortunately reduced by the operation of recovering theliquid LQ even when none exists.

Furthermore, if infrared light that has one of the abovementionedwavelengths is used for the detection beams La, then dual wavelengthlaser light may be emitted, wherein infrared light (laser light in the 2μm band) that has a wavelength of, for example, approximately 1940 nmand infrared light (laser light in the 3 μm band) that has a wavelengthof approximately 2950 nm are combined. Alternatively, detection beamsmay be emitted that combine a plurality of three or more laser lightsthat have wavelengths (or wavelength bands) that differ from oneanother.

Incidentally, the embodiment discussed above is constituted so that thedetection beams La are emitted substantially parallel to the surface ofan object, such as the substrate P or the substrate stage PST, and thepresence of the liquid LQ on the object is detected by detecting whetherthe liquid LQ is present in the optical paths of those detection beamsLa. In other words, if the liquid LQ is present on the object, then thedetection beams La must reliably irradiate the liquid LQ. Consequently,in order for the detection apparatus 60 to reliably emit the detectionbeams La to the liquid LQ present on the object, the detection beams Lapass on the inner side of an area away within a prescribed distance fromthe surface of the object. Specifically, the detection beams La are setso that they pass through the area away by up to 5.5 mm from the surfaceof the object. This point will now be explained referencing FIG. 8.

In FIG. 8, the liquid LQ on the object surface (in FIG. 8, the uppersurface 43 of the substrate stage PST) is disposed in a liquid droplet(water droplet) state. In this state, the following relationship isdefined:cos θ=1−(ρ×g×h ²)/(2×σ)  (1A)

where θ: contact angle of the liquid LQ with respect to the objectsurface;

ρ: liquid density;

h: height of liquid (liquid droplet);

σ: surface tension coefficient; and

g: gravitational acceleration.

The liquid LQ in the present embodiment is water, and therefore ρ=998(kg/m³) and σ=73×10⁻³ (N/m). Solving the abovementioned equation (1A)for h yields:h=[(2×σ)×(1−cos θ)/(ρ×g)]^(1/2)  (2A)

If the object surface is sufficiently liquid-repellent and if θ=180°(cos θ=−1), then h=5.46×10⁻³ (m), i.e., approximately 5.5 mm.

Because the value of the contact angle θ is actually less than 180°, thevalue of the height h is likewise less than 5.5 mm. For example, if theupper surface 43 is made of polytetrafluoroethylene (Teflon™), then thecontact angle θ of the liquid (water) LQ with respect to that uppersurface 43 is approximately 115°, and the height h is thereforeapproximately 4.6 mm. Furthermore, if the amount of the liquid LQ issufficient, then the value of the height h becomes a fixed value thatdoes not vary with the amount of that liquid LQ. Accordingly, by settingthe detection beams La so that they pass within an area of a height upto 5.5 mm from the object surface, in other words by setting thedistance D between the object surface and the detection beams La, whichare emitted substantially parallel to that object surface, to 5.5 mm orless, it is possible to reliably emit the detection beams La to theliquid (water) LQ present on the object surface.

Furthermore, if detecting the presence of the liquid LQ on the uppersurface of the substrate stage PST, including on the front surface ofthe substrate P, by emitting the detection beams La, for example, beforeor after the measurement process (step S2), or before or after theimmersion exposure process (step S4), then the substrate stage PST maybe driven in the Z axial direction to adjust the position of the uppersurface so that the detection beams La pass through the area within 5.5mm from the upper surface of the substrate stage PST. Alternatively, thepositions of the detection beams La may be adjusted by moving thedetection apparatus 60, including the light emitting portion 61, theoptical member 63, and the like, or by moving the positions of both thesubstrate stage PST and the detection beams La.

Furthermore, because the value of the height h varies in accordancewith, for example, the surface state (contact angle θ) of the object andthe type (physical property) of the liquid LQ used, if, for example, aliquid other than water is used as the liquid LQ, then the height hshould be derived from the abovementioned equation (2A), and thedistance D should be set based on that height h.

In addition, if the amount of the liquid LQ is small (if the size of theliquid droplet is small), then the value of the height h thereofdecreases; however, even in that case, the detection beams La can beemitted to the liquid (liquid droplet) LQ on the substrate stage PST byadjusting the positions of the substrate stage PST, the detection beamsLa, and the like.

The following explains another embodiment of the present invention. Inthe explanation below, components that are identical or equivalent tothose in the embodiment discussed above are assigned the identicalsymbols, and the explanations thereof are abbreviated or omitted.

FIG. 9 is a perspective view that depicts another embodiment of thepresent invention. As depicted in FIG. 9, the detection apparatus 60 hasa plurality of light emitting portions 61A-61H provided to the outerside of the substrate stage PST, and a plurality of light receivingportions 62A-62H provided so that they correspond to those lightemitting portions 61A-61H. These light emitting portions 61A-61H andlight receiving portions 62A-62H are fixed to the main column 3 or thelike.

The detection apparatus 60 emits the detection beams La from each of thelight emitting portions 61A-61H so that they are substantially parallelto the XY plane, i.e., substantially parallel to the substrate P and theupper surface 43 of the substrate stage PST. The plurality of detectionbeams La emitted from each of the light emitting portions 61A-61H isemitted to the vicinity of the edge portion LG of the immersion area AR2of the liquid LQ formed on the substrate P. Furthermore, the detectionapparatus 60 emits the detection beams La using the light emittingportions 61A-61H from a plurality of mutually different directions to aplurality of positions in the vicinity of the edge portion LG of theimmersion area AR2. Specifically, of the plurality of provided lightemitting portions 61A-61H, the light emitting portions 61A, 61B emit thedetection beams La to the vicinity of the edge portion LG of theimmersion area AR2 from directions substantially parallel to the X axialdirection, and the light emitting portions 61E, 61F emit the detectionbeams La from directions substantially parallel to the Y axialdirection. In addition, the light emitting portions 61C, 61D emit thedetection beams La to the edge portion LG of the immersion area AR2 froma direction diagonal to the X axis (Y axis) direction, and the lightemitting portions 61G, 61H emit the detection beams La from aninclination direction different from the detection beams La emitted fromthe light emitting portions 61C, 61D. Namely, the optical paths of theplurality of detection beams La emitted from the light emitting portions61A-61H are set so that they surround the immersion area AR2.

In addition, the two detection beams La respectively emitted from thelight emitting portions 61A, 61B are provided so that they are emittedto both sides of the vicinity of the edge portion LG of the immersionarea AR2, which is thereby interposed therebetween. Likewise, the twodetection beams La respectively emitted from the light emitting portions61C, 61D are provided so that they are emitted to both sides of thevicinity of the edge portion LG of the immersion area AR2, the twodetection beams La respectively emitted from the light emitting portions61E, 61F are provided so that they are emitted to both sides of thevicinity of the edge portion LG of the immersion area AR2, and the twodetection beams La respectively emitted from the light emitting portions61G, 61H are provided so that they are emitted to both sides of thevicinity of the edge portion LG of the immersion area AR2.

The control apparatus CONT performs the immersion exposure by formingthe immersion area AR2 on the substrate P in a state wherein thedetection beams La are emitted by each of the light emitting portions61A-61H and then emitting the exposure light EL through the liquid LQupon the substrate P. In other words, the control apparatus CONTperforms the detection operation using the detection apparatus 60 andthe exposure of the substrate P in parallel. Of course, the detectionoperation may be performed in parallel with the measurement processdiscussed above.

At this point, when the immersion area AR2 is formed on the substrate Pat the prescribed position and in the desired state (the desired sizeand shape), the optical paths of the detection beams La are set topositions away from the edge portion LG of the immersion area AR2 by aprescribed distance toward the outer side. Namely, when the immersionarea AR2 is formed in the desired state, the detection beams Larespectively emitted from each of the light emitting portions 61A-61Hare provided so that they do not irradiate the liquid LQ of theimmersion area AR2 but arrive at the light receiving portions 62A-62Hwithout passing through the liquid LQ.

In other words, the optical paths of the plurality of detection beams Laemitted to the vicinity of the edge portion LG of the immersion area AR2are set in accordance with a preset target shape and size of theimmersion area AR2.

For example, if the immersion area AR2 formed between the projectionoptical system PL and the substrate P during, for example, the immersionexposure of the substrate P exceeds a preset prescribed (desired) size,the liquid LQ is disposed in the optical path of any of the plurality ofdetection beams La. In addition, even when the liquid LQ flows out fromabove the substrate P or cannot be held on the image plane side of theprojection optical system PL and flows out from between the front endportion of the projection optical system PL and the substrate P, theliquid LQ is disposed in the optical paths of the detection beams La.Consequently, based on the light receiving result of any of the lightreceiving portions 62A-62H, the detection apparatus 60 can detect theoccurrence of an abnormality, such as the size of the immersion area AR2exceeding a desired size, the outflow of the liquid LQ, and the like.Based on the detection results of the detection apparatus 60, thecontrol apparatus CONT performs control in order to set the size of theimmersion area AR2 to the desired size, for example, by reducing theamount of liquid supplied per unit of time by the liquid supplymechanism 10, increasing the amount of liquid recovered per unit of timeby the liquid recovery mechanism 20, and the like. In addition, if thedetection results of the detection apparatus 60 are determined to beabnormal, i.e., the immersion area AR2 exceeds a prescribed size or theliquid LQ has flowed out from above the substrate P, then the controlapparatus CONT stops the supply of the liquid LQ by the liquid supplymechanism 10. Thereby, it is possible to prevent the outflow of theliquid LQ. Furthermore, based on the detection results of the detectionapparatus 60, the control apparatus CONT may also stop the movement ofthe substrate stage PST, or stop the operation of exposing the substrateP.

In addition, because at least two of the plurality of detection beams Laare respectively emitted to both sides of the vicinity of the edgeportion LG of the immersion area AR2 and, in the present embodiment, theoptical paths of the plurality of detection beams La are set so thatthey surround the immersion area AR2, it is also possible to detect thedirection in which the liquid LQ flows out from the immersion area AR2.Accordingly, to suppress the outflow of the liquid LQ in that direction,the control apparatus CONT, for example, uses the flow controllers 16A,16B and the like to separately adjust the amounts of liquid suppliedfrom the plurality of liquid supply ports 12A, 12B, or separatelyadjusts the amounts of liquid recovered through the plurality of liquidrecovery ports 22A, 22B.

In addition, if the substrate stage PST that holds the substrate P movesat high speed in a state wherein the immersion area AR2 of the liquid LQis formed between the projection optical system PL and the substrate P,then there is a possibility that the liquid LQ of the immersion area AR2will be dragged by the movement of the substrate P and will flowoutwards or the size of the immersion area AR2 may be increased. In sucha case, the speed of the movement of the substrate stage PST should bedecreased. Thus, it is also possible to suppress the outflow of theliquid LQ by controlling the drive of the substrate stage PST, such asby adjusting the speed or the direction of the movement of the substratestage PST.

In addition, when the detection apparatus 60 detects the direction inwhich the liquid LQ flowed out, for example, after the immersionexposure is finished, the substrate stage PST may be moved in the X andY directions in accordance with that direction so that the liquid LQthat flowed out is disposed below the liquid recovery ports 22, and maythen be recovered.

In addition, in the present embodiment as well, the accuracy ofdetecting the liquid LQ can be improved by using infrared light of aprescribed wavelength for the detection beams La.

FIG. 10 is a side view that depicts another embodiment of the presentinvention, and FIG. 11 is a plan view thereof. As depicted in FIG. 10and FIG. 11, the detection apparatus 60 emits the detection beams Lafrom the light emitting portion 61 to the immersion area AR2 of theliquid LQ formed between the projection optical system PL and thesubstrate P. In the present embodiment, the light emitting portion 61emits the plurality of detection beams La, which are arrayed in the Yaxial direction, along the X axial direction. In the present embodiment,the control apparatus CONT performs, in parallel, the exposure operationof the substrate P, the measurement operation, and the detectionoperation using the detection apparatus 60.

Based on the light receiving results of the light receiving portion 62that receives the detection beams La emitted from the light emittingportion 61 to a plurality of positions in the immersion area AR2, thedetection apparatus 60 can derive the size of the immersion area AR2formed on the substrate P.

The light receiving portion 62 has a plurality of light receivingdevices corresponding to the abovementioned plurality of detection beamsLa. The positional information of these light receiving devices is knownin advance by, for example, design values. If the detection beams La1,which are a portion of the plurality of detection beams La emitted fromthe light emitting portion 61, are emitted to the immersion area AR2,then they do not arrive at the corresponding light receiving devices ofthe light receiving portion 62, or the amount of light received by thoselight receiving devices decreases. On the other hand, the detectionbeams La2, which are the remaining portion, arrive at the lightreceiving portion 62 without passing through the immersion area AR2.Accordingly, the detection apparatus 60 can derive the size of theimmersion area AR2 based on the light receiving results of the lightreceiving devices of the light receiving portion 62 that received thedetection beams La1, and on the positional information of those lightreceiving devices.

Furthermore, in the present embodiment, the detection apparatus 60 canderive the size of the immersion area AR2 in the Y axial directionbecause the detection beams La are emitted to the liquid LQ from the Xaxial direction; however, the detection apparatus 60 can also derive thesize of the immersion area AR2 in the X axial direction by emitting thedetection beams La to the immersion area AR2 from the Y axial direction.In addition, it is of course also possible to emit the detection beamsLa from a direction diagonal to the X axial direction within the XYplane. Furthermore, the detection apparatus 60 (or the control apparatusCONT) can derive the shape of the immersion area AR2 by arithmeticallyprocessing the light receiving results produced when the detection beamsLa were emitted to the immersion area AR2 from a plurality ofdirections.

Furthermore, based on the detection results of the detection apparatus60, the control apparatus CONT controls the operation of either theliquid supply mechanism 10 or the liquid recovery mechanism 20, or both.For example, if it is detected that the immersion area AR2 is greaterthan a prescribed size, then, in order to make the immersion area AR2the desired size, the control apparatus CONT, for example, reduces theamount of liquid supplied per unit of time by the liquid supplymechanism 10, or increases the amount of liquid recovered per unit oftime by the liquid recovery mechanism 20. Alternatively, if it isdetected that the immersion area AR2 is greater than a prescribed size,then the control apparatus CONT may also stop the supply of the liquidLQ by the liquid supply mechanism 10. Conversely, if it is detected thatthe immersion area AR2 is less than a prescribed size, then, in order tomake the immersion area AR2 the prescribed size, the control apparatusCONT, for example, increases the amount of liquid supplied per unit oftime by the liquid supply mechanism 10, or decreases the amount ofliquid recovered per unit of time by the liquid recovery mechanism 20.

In addition, if the liquid LQ is disposed in the optical paths of eachof the plurality of detection beams La and the detection beams La arenot received with the prescribed light quantity at the light receivingportion 62, then the control apparatus CONT determines that anabnormality has occurred, such as the outflow of the liquid LQ fromabove the substrate P. In that case, the control apparatus CONT stopsthe supply of the liquid LQ by the liquid supply mechanism 10.

In addition, when the shape of the immersion area AR2 greatly differsfrom the preset target shape, the shape of the immersion area AR2 canalso be adjusted by, for example, separately adjusting the amounts ofliquid supplied per unit of time from the plurality of liquid supplyports 12A, 12B, separately adjusting the amounts of liquid recovered perunit of time through the plurality of liquid recovery ports 22A, 22B, orcontrolling the drive of the substrate stage PST.

In addition, because the present embodiment has a constitution whereinthe detection apparatus 60 also emits the detection beams La onto theoptical path of the exposure light EL within the immersion area AR2, itis also possible to detect, for example, a gas portion present betweenthe optical element 2 at the front end of the projection optical systemPL and the substrate P. Accordingly, if the detection apparatus 60detects the gas portion, i.e., if a break in the liquid of the immersionarea AR2 is detected, then, in order to eliminate the gas portion, thecontrol apparatus CONT increases the amount of liquid supplied by theliquid supply mechanism 10, decreases the amount of liquid recovered bythe liquid recovery mechanism 20, and the like. Alternatively, if a gasportion is generated, then the pattern image will not be satisfactorilytransferred onto the substrate P and the control apparatus CONT mayconsequently stop the exposure thereof.

Furthermore, in the present embodiment, the light emitting portion 61emits a plurality of arrayed detection beams La, but it may emit a sheetlight beam so that it covers the immersion area AR2. A so-called lasersheet light generated by, for example, passing the laser light beamemitted from a laser light source through an optical system that has apinhole or a cylindrical lens, can be used as the sheet light beam.

In addition, the irradiation area by the sheet light beam is set so thatits size is at least greater than the target size of the immersion areaAR2. In so doing, if the immersion area AR2 is the desired size, thenthe light receiving portion 62 can receive light of the detection beamsLa2.

Furthermore, in the present embodiment as well, the accuracy ofdetecting the presence of the liquid LQ can be improved by usinginfrared light of a prescribed wavelength for the detection beams La.

Furthermore, in each of the embodiments discussed above, the pluralityof detection beams La are emitted so that they are arrayed in thehorizontal direction, but they may be emitted so that they are arrayedin the vertical direction. In so doing, if the space between theprojection optical system PL and the substrate P is filled with theliquid LQ, e.g., even if a situation arises wherein the liquid LQ isdisposed in the vicinity of the front surface of the substrate P while,on the other hand, a gas portion has formed in the vicinity of theliquid contact surface 2A of the optical element 2 of the projectionoptical system PL, then that gas portion can be satisfactorily detected,and additionally, the liquid that adheres to the liquid contact surface2A of the optical element 2 or the lower surface 70A of the passagewayforming member 70 can also be detected after the liquid LQ has beenrecovered.

Incidentally, in each of the embodiments discussed above, the detectionbeams La are emitted substantially parallel to the upper surface of thesubstrate stage PST; however, if, for example, a recessed portion isformed on the substrate stage PST and the liquid LQ remains on (adheresto) the inner side of that recessed portion (e.g., on the substrateholder PH), then it will be difficult to detect the liquid LQ on theinner side of that recessed portion if the detection beams La areemitted substantially parallel to the upper surface of the substratestage PST. In that case, the detection apparatus emits the detectionbeams La to the upper surface of the substrate stage PST from verticallyabove, or from diagonally above.

FIG. 12 is a schematic diagram that depicts a state wherein the liquidLQ disposed on the inner side of the recessed portion 1 formed on thesubstrate stage PST is being detected. A detection apparatus 65 depictedin FIG. 12 has the combined functions of the light emitting portion thatemits the detection beams La and the light receiving portion thatreceives those beams. Furthermore, the detection apparatus 65 emits thedetection beams La to the recessed portion 1, which is formed on thesubstrate stage PST and wherein the substrate holder PH is disposed,from above; receives the light from that recessed portion 1; and, basedon that light receiving result, detects whether the liquid LQ is presenton the inner side of the recessed portion 1. The detection apparatus 65emits the detection beams La to the recessed portion 1 from above.

If the liquid LQ is not present on the inner side of the recessedportion 1, which includes an upper surface (holding surface) PHa of thesubstrate holder PH, then the reflected light of the detection beams Laemitted to the recessed portion 1 is received by the detection apparatus65 with a prescribed light intensity. On the other hand, if the liquidLQ is present on the inner side of the recessed portion 1, then thedetection beams La emitted to the recessed portion 1 are scattered orabsorbed by the liquid LQ, and that reflected light is consequentlyreceived by the detection apparatus 65 with a light intensity weakerthan the abovementioned prescribed light intensity. Based on the lightreceiving results of the reflected light, it is possible to detectwhether the liquid LQ is present on the inner side of the recessedportion 1.

Furthermore, in the present embodiment as well, if emitting thedetection beams La to the recessed portion 1 (the upper surface of thesubstrate stage PST), then it is possible to perform detection whilemoving the substrate stage PST in the XY directions with respect to thedetection beams La. Of course, it is also possible to perform detectionwhile moving the detection beams La emitted from the detection apparatus65, and it is also possible to perform detection while moving both thesubstrate stage PST and the detection beams La. Thus, it is possible todetect the presence of the liquid LQ in a large area on the inner sideof the recessed portion 1 by performing detection while moving eitherthe substrate stage PST or the detection beams La emitted from thedetection apparatus 65, or both.

In addition, in this case as well, the accuracy of detecting the liquidLQ can be improved by using infrared light of a prescribed wavelengthfor the detection beams La.

Furthermore, the recessed portion is not limited to one wherein thesubstrate holder PH is disposed, and includes all recessed portionsformed on the objects, such as the substrate stage PST, that aredisposed lower than the front end portion of the projection opticalsystem PL.

Incidentally, the detection apparatus 65 can detect whether the liquidLQ is present on the substrate holder PH on the inner side of therecessed portion 1, but the emission of the detection beams La to thesubstrate holder PH by the detection apparatus 65 is preferablyperformed before loading the substrate P on the substrate holder PH,i.e., before step S1, which was explained referencing FIG. 7.

Namely, if the detection apparatus 65 has detected the presence of theliquid LQ on the substrate holder PH, then the control apparatus CONTuses a prescribed liquid removal mechanism 25 to collect that liquid LQon the substrate holder PH, as depicted in FIG. 13A. The liquid removalmechanism 25 depicted in FIG. 13A has a suction nozzle that collects theliquid LQ by suction. The suction nozzle approaches the substrate holderPH from above, and collects the liquid LQ thereon. Furthermore, theliquid removal mechanism 25 may also have a constitution wherein a gasis blown against the substrate holder PH to blow off the liquid LQ, ormay have a constitution wherein the liquid LQ is absorbed by using aliquid absorbing member. Furthermore, after the liquid LQ on thesubstrate holder PH is collected, the substrate P is loaded on thesubstrate holder PH by a loading apparatus 80, as depicted in FIG. 13B.

If, unfortunately, the substrate P is loaded on the substrate holder PHin a state wherein the liquid LQ is disposed on the substrate holder PH,then there is a possibility that the liquid LQ will function as alubricating film and cause the mispositioning of the substrate P withrespect to the substrate holder PH, and will thereby degrade exposureaccuracy, measurement accuracy, and the like. In addition, if aconstitution is adopted wherein the substrate holder PH holds thesubstrate P by a vacuum suction system, then a problem still ariseswherein the liquid LQ flows into the vacuum system through the vacuumsuction holes. Incidentally, if the detection apparatus 65 detectswhether the liquid LQ is present on the substrate holder PH before thesubstrate P is loaded on the substrate holder PH and the liquid LQ isthen detected, then it is possible, by recovering the liquid LQ usingthe liquid removal mechanism 25, to reliably hold the substrate P to thesubstrate holder PH when loading the substrate P thereon.

Furthermore, the operation of detecting the liquid LQ on the substrateholder PH using the detection apparatus 65 can of course be performedafter unloading the substrate P, for which the immersion exposure hasfinished, from the substrate holder PH, i.e., after step S6, which wasexplained referencing FIG. 7. In addition, the liquid removal mechanism25 may be attached to the loading apparatus 80.

Furthermore, in addition to detecting whether the liquid LQ is presenton the inner side of the recessed portion, the detection apparatus 65can of course also detect whether the liquid LQ is present on a flatsurface, such as on the front surface of the substrate P and on theupper surface 43 of the substrate stage PST. In addition, when detectingwhether the liquid LQ is present on the upper surface 43 of thesubstrate stage PST in a state wherein the substrate P is loaded on thesubstrate holder PH, the detection operation using the detectionapparatus 65 and the operation of exposing the substrate P may beperformed in parallel.

Furthermore, as depicted in FIG. 14, if a constitution is adoptedwherein the substrate holder PH is movable in the Z axial direction andin the θX and θY directions with respect to the plate member 43 of thesubstrate stage PST, then, when detecting whether the liquid LQ ispresent on the substrate holder PH, a holder drive mechanism PHL thatdrives the substrate holder PH may be used to make the upper surface PHaof the substrate holder PH substantially flush with the upper surface 43of the substrate stage PST, and the detection beams La may then beemitted substantially parallel to the upper surface PHa of the substrateholder PH and the upper surface 43 of the substrate stage PST.

FIG. 15 depicts another embodiment of the present invention. In FIG. 15,the substrate stage PST is provided with a detection apparatus 66 thatdetects whether the liquid LQ is present, for example, on the lowersurface 2A of the optical element 2 at the front end portion on theimage plane side of the projection optical system PL, or on portionsprovided in the vicinity thereof, such as the lower surface 70A of thepassageway forming member 70. Similar to the detection apparatus 65 thatwas explained referencing FIG. 12, the detection apparatus 66 has thecombined functions of the light emitting portion that emits thedetection beams La and the light receiving portion that receives thosebeams. The light emitting portion and the light receiving portion of thedetection apparatus 66 are provided at a position on the substrate stagePST outside of the substrate holder PH, specifically on the uppersurface 43.

The detection apparatus 66 emits the detection beams La to the lowersurface 2A of the optical element 2 of the projection optical system PL,the lower surface 70A of the passageway forming member 70, and the likebefore or after the exposure operation in a state wherein the space onthe image plane side of the projection optical system PL is filled withthe liquid LQ, or before or after the measurement operation.Furthermore, if the adhering liquid LQ has been found, then that liquidLQ is removed by a prescribed liquid removal mechanism. If the liquid LQadhering to the optical element 2 and the like is left as it is, then aproblem will arise wherein a water residue (a so-called watermark) willbe formed on the front surface of the optical element 2; however, thedetection apparatus 66 can detect whether the liquid LQ has adhered tothe optical element 2, and, if it has adhered, then the occurrence ofthe abovementioned problem can be prevented by removing that liquid LQ.

Furthermore, if the detection apparatus 66 has detected the adherence ofthe liquid LQ to the optical element 2, then the control apparatus CONTmay supply the liquid LQ to the image plane side of the projectionoptical system PL so as to form the immersion area AR2 and wet theoptical element 2, as depicted in FIG. 16, for example. In the exampledepicted in FIG. 16, the immersion area AR2 is formed by supplying theliquid LQ between the projection optical system PL and the upper surface43 of the substrate stage PST in a state wherein the projection opticalsystem PL and the upper surface 43 of the substrate stage PST aredisposed so that they oppose one another. In so doing, it is possible toprevent the problem wherein a watermark is formed.

When unloading the substrate P for which the exposure process hasfinished from the substrate stage PST, that substrate P is lifted fromthe substrate holder PH (the substrate stage PST) by, for example, alift mechanism that is provided to the substrate holder PH, and the rearsurface of that substrate P and the holding surface PHa of the substrateholder PH thereby become separated from each other. At this time, thedetection apparatus 66 may be used to detect whether the liquid LQ hasadhered to the rear surface of the lifted substrate P. In this case, thedetection apparatus 66 should be provided in advance with an emissionportion, which emits detection beams from diagonally below to the rearsurface of the substrate P, and a light receiving portion that receivesthe reflected light thereof, and should detect whether the liquid hasadhered to the rear surface of the substrate P based on the lightreceiving result of the light receiving portion. Alternatively, thedetection apparatus 66 may be provided with an imaging apparatus (CCD orthe like) that is capable of imaging the rear surface of the substrateP, and may detect whether the liquid has adhered to the rear surface ofthe substrate P by processing the image. If the liquid LQ has adhered tothe rear surface of the substrate P, then the control apparatus CONTeliminates that liquid LQ on the rear surface of the substrate P by, forexample, blowing gas thereagainst using a prescribed liquid removalmechanism. In so doing, even if a constitution is adopted wherein, forexample, an unloading apparatus holds the rear surface of the substrateP by suction through vacuum suction holes, it is possible to avoidproblems, such as the liquid LQ entering the interior of the vacuumsuction holes, or the liquid LQ forming a lubricating film and therebycausing the mispositioning of the substrate P, and it is thereforepossible to reliably hold the substrate P to a support surface of theunloading apparatus.

In addition, if the liquid adhering to the rear surface of the substrateP is detected, then the unloading of that substrate P may be stopped, awarning, for example, may be issued, and the operator may be requestedto remove the substrate P. In this case as well, it is possible toprevent, for example, the adherence of the liquid to the unloadingapparatus.

Furthermore, the detection of whether the liquid has adhered to the rearsurface of the substrate P may be performed after the substrate P isunloaded from the substrate stage PST, i.e., after the unloadingapparatus (not shown) has received the substrate P. Furthermore, if theadherence of the liquid to the rear surface of the substrate P isdetected, then the liquid should be removed, a warning should be issued,or the like. However, in this case, there is a possibility that theliquid will adhere to the unloading apparatus (not shown), and it istherefore necessary to remove that liquid or clean the unloadingapparatus.

FIG. 17 is a perspective view that depicts another embodiment of thepresent invention, FIG. 18A is a side view of FIG. 17 viewed from thearrow A direction, and FIG. 18B is a cross sectional view along the B-B′line in FIG. 17. In FIG. 17, FIG. 18A and FIG. 18B, the detectionapparatus 60 has a light emitting portion 61K that emits a plurality ofdetection beams La arrayed in the Z axial direction to the upper surface43 of the substrate stage PST, and a light receiving portion 62Kdisposed at a prescribed position with respect to the detection beamsLa. The light receiving portion 62K has a plurality of light receivingdevices corresponding to the plurality of detection beams La emittedfrom the light emitting portion 61K.

The light emitting portion 61K and the light receiving portion 62K arefixed to, for example, the main column 3, and the detection beams Laemitted from the light emitting portion 61K are set so that they passthrough a position away from the projection optical system PL.Furthermore, the light emitting portion 61K and the light receivingportion 62K can be provided, for example, in the vicinity of the loadposition where the substrate P is loaded on the substrate stage PST, inthe vicinity of the unload position where the substrate P is unloadedfrom the substrate stage PST, at a prescribed position between the loadposition and an exposure position (a position below the projectionoptical system PL), or at a prescribed position between the unloadposition and the exposure position.

In the embodiment explained referencing FIG. 6 and the like, the sizeand shape of the liquid LQ in the horizontal direction is detected byemitting a plurality of detection beams La so that they are arrayed inthe horizontal direction (XY directions); however, in the presentembodiment, the plurality of detection beams La, which are arrayed inthe vertical direction (Z axial direction), are emitted, and thedetection apparatus 60 can therefore derive the height of the liquid LQ(liquid droplet) based on the light receiving results of the lightreceiving portion 62K.

The control apparatus CONT can also detect the height h of the liquid LQon the upper surface 43 using the detection apparatus 60 and, based onthat detection results, derive the contact angle θ of the liquid LQ withrespect to the upper surface 43, as depicted in FIG. 18A. Specifically,the control apparatus CONT can detect the height h of the liquid LQusing the detection apparatus 60 and then calculate the contact angle θbased on the abovementioned equation (1A).

In addition, in the embodiment depicted in FIG. 17, the detection beamsLa are emitted substantially parallel to the Y axial direction; however,the control apparatus CONT can emit the detection beams La while movingthe substrate stage PST in the X axial direction, which is the directionthat intersects with the optical paths of the detection beams La. Byarithmetically processing the plurality of light receiving results ofthe light receiving portion 62K corresponding to the plurality ofpositions of the substrate stage PST, the control apparatus CONT canderive the shape of the liquid (liquid droplet) LQ, in the Z axialdirection, that is present on the substrate stage PST. Furthermore,based on the derived shape of the liquid (liquid droplet) LQ, thecontrol apparatus CONT can derive the affinity of the liquid LQ for theupper surface 43 of the substrate stage PST, specifically the contactangle θ of the liquid LQ with respect to the upper surface 43, asdepicted in FIG. 18B.

Incidentally, it is preferable that the upper surface 43 of thesubstrate stage PST (the surface of the object opposing the lowersurface 2A of the projection optical system PL) is liquid-repellent. Bymaking the upper surface 43 liquid repellent, even if the liquid LQremains on the upper surface 43, that liquid LQ can be smoothlycollected. In addition, it is preferable that the front surface of thesubstrate P, whereon the immersion area AR2 of the liquid LQ is formed;the upper surface 301A of the fiducial member 300; the upper surface401A of the luminous flux intensity nonuniformity sensor 400; the uppersurface 501A of the spatial image measuring sensor 501; and the like areall liquid-repellent. By making these upper surfaces and the frontsurface of the substrate P liquid-repellent, the immersion area AR2 ofthe liquid LQ can be satisfactorily formed between the projectionoptical system PL and those surfaces, and the liquid can be smoothlyrecovered. In addition, by making the front surface of the substrate Pliquid-repellent, the immersion area AR2 formed between the projectionoptical system PL and the front surface of the substrate P can besatisfactorily maintained even when immersion-exposing the substrate Pwhile moving such. Likewise, it is also conceivable to perform themeasurement process while moving the substrate stage PST in a statewherein the immersion area AR2 of the liquid LQ is formed on each of theupper surfaces 301A, 401A, 501A, and the immersion area AR2 can besatisfactorily maintained by making the upper surfaces 301A, 401A, 501Aliquid-repellent.

Incidentally, there is a possibility that the liquid repellency of theupper surface of the substrate stage PST, including the upper surface301A of the fiducial member 300 and the upper surfaces 401A, 501A of theupper plates 401, 501, will degrade over the course of time. Forexample, if, in order to make the upper surface of the substrate stagePST and the like liquid-repellent, they are coated with a liquidrepellent material, or if the abovementioned members, upper plates, andthe like are made of a liquid repellent material, then there is apossibility that that liquid repellency will degrade if they areirradiated by the exposure light EL. In particular, if, for example,fluorine based resin is used for the liquid repellent material andultraviolet light is used for the exposure light EL, then the liquidrepellency of the upper surface of the substrate stage PST and the liketends to degrade (tends to become lyophilic). In so doing, the liquid LQtends to remain on the substrate stage PST, which invites a degradationof the exposure accuracy, the measurement accuracy, and the like.

Accordingly, the control apparatus CONT uses the detection apparatus 60to periodically derive the contact angle θ of the liquid LQ with respectto the upper surface 43 of the substrate stage PST, including the uppersurface 301A of the fiducial member 300 and the upper surfaces 401A,501A of the upper plates 401, 501, i.e., the affinity of the liquid LQfor the upper surface 43. By deriving the contact angle θ, it ispossible to ascertain the level of liquid repellency of the uppersurface 43 of the substrate stage PST. If the derived contact angle θ(liquid repellency level) is less than a permissible value of a presetcontact angle (liquid repellency level), then appropriate measures aretaken with respect to the upper surface 43 of the substrate stage PST.

For example, if the contact angle θ of the liquid LQ with respect to theupper surface 301A of the fiducial member 300, which is replaceablydisposed on the substrate stage PST, has been detected and is less thanthe abovementioned permissible value, then that fiducial member 300 isreplaced with another (new) fiducial member 300 that has sufficientliquid repellency.

Likewise, if the contact angle θ of the liquid LQ with respect to theupper surface 401A of the upper plate 401, the upper surface 501A of theupper plate 501, or the like has been detected and is less than theabovementioned permissible value, then that upper plate 401 or thatupper plate 501 is replaced with another (new) upper plate 401 or upperplate 501, respectively, that has sufficient liquid repellency.

Alternatively, if the contact angle θ of the liquid LQ with respect tothe upper surface 43 has been detected, then it is also possible, basedon that detected contact angle θ, to replace the plate member 43P, whichhas the upper surface 43, of the substrate stage PST.

In addition, the control apparatus CONT can of course use the detectionapparatus 60 to detect the contact angle θ with respect to the frontsurface of the substrate P, which is held on the substrate stage PST.

In addition, by deriving the shape of the droplet of the liquid LQ usingthe detection apparatus 60 depicted in FIG. 17 in a state wherein thesubstrate stage PST is inclined, it is also possible to derive thedynamic contact angle, drop angle, and the like of the liquid LQ on thesubstrate stage PST (the substrate P).

Furthermore, when detecting the contact angle θ of the liquid LQ withrespect to the upper surface 43 and the like, a small amount of theliquid (a liquid droplet) should be supplied to the upper surface 43from the liquid supply ports 12 of the liquid supply mechanism 10, andthe substrate stage PST should be moved so that that liquid LQ disposedon the upper surface 43 is disposed in the optical paths of thedetection beams La emitted by the light emitting portion 61K.

In addition, if the front surface of the substrate P, the upper surfaceof the substrate stage PST including the upper surfaces 301A, 401A,501A, and the like are not sufficiently liquid-repellent, then there isa possibility that, as discussed above, it will become difficult tosatisfactorily maintain the immersion area AR2, e.g., a problem willoccur wherein the liquid LQ flows out of the immersion area AR2.Accordingly, the occurrence of such problems can be avoided bycontrolling the operation of either the liquid supply mechanism 10 orthe liquid recovery mechanism 20, or both, based on the detected contactangle θ. For example, if it is determined, based on the detected contactangle θ, that the level of liquid repellency of the front surface of thesubstrate P is low, then the control apparatus CONT can perform control,such as reducing the amount of liquid supplied by the liquid supplymechanism 10, increasing the amount of liquid recovered (recovery force)by the liquid recovery mechanism 20, and the like when performingimmersion exposure while moving the substrate P.

Alternatively, based on the detected contact angle θ, the controlapparatus CONT can also adjust the travel speed of the substrate P(substrate stage PST) when immersion-exposing the substrate P whilemoving such. For example, if it is determined that the liquid repellencylevel on the substrate P is low, then the control apparatus CONT canreduce the speed of movement of the substrate P. It is thereby possibleto reduce the possibility that the liquid LQ will flow out of thedesired area.

In addition, there is also a possibility that the pressure of theimmersion area AR2 will change in accordance with the contact angle θ(liquid repellency level) of the front surface of the substrate P; ifpressure fluctuations occur, then there is a possibility that,unfortunately, those fluctuations will slightly deform the substrate P,the substrate stage PST, and the like. For example, if the liquidrepellency level is high, then the immersion area AR2 will becomepositively pressurized, and if the liquid repellency level is low, thenthe immersion area AR2 will become negatively pressurized. Therefore,based on the detected contact angle θ, the liquid supply quantity, theliquid recovery quantity, and the like may be adjusted to reduce theforce that affects the substrate P, the substrate stage PST, and thelike.

Furthermore, in the present embodiment as well, the accuracy ofdetecting the contact angle θ can be improved by using infrared light ofa prescribed wavelength for the detection beams La.

In addition, in the embodiment discussed above, an imaging apparatus canalso be adopted as the detection apparatus 60, which would enable theoperator and the like to easily ascertain the state of the liquiddisposed on the substrate stage PST (substrate P) and the state of theadhering liquid.

In addition, the present invention may also be adapted to a twin stagetype exposure apparatus that has two stages on which substrates to beprocessed, such as wafers, are separately disposed, and which areindependently movable in the X and Y directions. A twin stage typeexposure apparatus is disclosed in, for example, Japanese PublishedUnexamined Patent Application No. H10-163099 and Japanese PublishedUnexamined Patent Application No. H10-214783 (corresponding to U.S. Pat.Nos. 6,341,007, 6,400,441, 6,549,269, and 6,590,634), Published JapaneseTranslation No. 2000-505958 of the PCT International Publication(corresponding U.S. Pat. No. 5,969,441), or U.S. Pat. No. 6,208,407, andthese disclosures are each hereby incorporated by reference in itsentirety to the extent permitted by the national laws and regulations ofthe designated states (or elected states) designated by the presentinternational patent application.

FIG. 19 is a plan view that depicts a schematic constitution of a twinstage type exposure apparatus. The twin stage type exposure apparatushas first and second substrate stages PST1, PST2, which are eachindependently movable on a common base. The twin stage type exposureapparatus has an exposure station ST1 and a measurement and exchangestation ST2; furthermore, the illumination optical system IL, the maskstage MST, the projection optical system PL, and the like, which wereexplained referencing FIG. 1, are mounted on the exposure station ST1.In addition, various measurement systems, such as the substratealignment system and the focus leveling detection system, are mounted onthe measurement and exchange station ST2.

The basic operation of such a twin stage type exposure apparatus is, forexample, as follows: during the exposure process of the substrate P onthe second substrate stage PST2 at the exposure station ST1, thesubstrate P on the first substrate stage PST1 is replaced and themeasurement process is performed at the measurement and exchange stationST2. Furthermore, when each of these procedures is finished, the secondsubstrate stage PST2 moves to the measurement and exchange station ST2and, parallel thereto, the first substrate stage PST1 moves to theexposure station ST1 where, this time, the measurement and replacementprocesses are performed on the second substrate stage PST2, and theexposure process is performed on the substrate P on the first substratestage PST1.

When the exposure process at the exposure station ST1 is finished, thesubstrate stage PST, which moved to the measurement and exchange stationST2, moves to an unload position ST3 in order to unload the substrate Pfor which the exposure process has finished. Furthermore, as depicted inFIG. 19, the detection apparatus 60, which detects whether the liquid LQis present on the substrate P, the substrate stage PST, and the like, isprovided on a movement path of the substrate stage PST2 that finishedthe exposure process and moves to the unload position ST3. The controlapparatus CONT uses the detection apparatus 60 to detect whether theliquid LQ is present on the substrate P, the substrate stage PST, andthe like before the substrate stage PST that finished the exposureprocess arrives at the unload position ST3. When the detection apparatus60 is used to detect the presence of the liquid LQ, the controlapparatus CONT emits the detection beams La from the light emittingportion 61 while moving the substrate stage PST to the unload positionST3. Furthermore, the detection beams La may be emitted in a statewherein the substrate stage PST is temporarily stopped. Furthermore, ifthe detection apparatus 60 does not detect the liquid LQ, then thecontrol apparatus CONT moves the substrate stage PST to the unloadposition ST3 and uses the unloading apparatus to unload the substrate Pon the substrate stage PST. On the other hand, if the detectionapparatus 60 detects the liquid LQ, then the control apparatus CONT canremove that liquid LQ using a prescribed liquid removal mechanism, whichis provided in advance at the unload position ST3 and the like, and canalso remove that liquid LQ by returning the substrate stage PST to themeasurement and exchange station ST2 or to the exposure station ST1 andthen using a prescribed liquid removal mechanism, which is provided inadvance, at the exposure station ST1 or the measurement and exchangestation ST2. Furthermore, after the removal of the liquid LQ has beenverified, the control apparatus CONT moves the substrate stage PST tothe unload position ST3 and unloads the substrate P. In this case, thedetection apparatus 60 may be constituted as depicted in FIG. 17, andnot only detect the presence of the liquid LQ, but also measure thecontact angle θ thereof.

In addition, the present invention can be adapted to an exposureapparatus that has an exposure stage that is capable of holding andmoving the substrate to be processed, such as a wafer, and a measurementstage that has measurement members, such as various fiducial members andmeasurement sensors. In this case, at least some of the variousmeasurement sensors and fiducial members disposed on the substrate stagePST in the embodiments discussed above can be disposed on themeasurement stage, and the detection apparatus 60 can be used to detectthe liquid LQ on the measurement stage. The exposure apparatus havingthe exposure stage and the measurement stage is disclosed in, forexample, Japanese Published Unexamined Patent Application No.H11-135400, the disclosure of which is hereby incorporated by referencein its entirety to the extent permitted by the national laws andregulations of the designated states (or elected states) designated bythe present international patent application.

As discussed above, the liquid LQ in the present embodiment is water.Pure water is advantageous because it can be easily obtained in largequantities at a semiconductor fabrication plant and the like, andbecause pure water has no adverse impact on the optical element (lens),the photoresist on the substrate P, and the like. In addition, becausepure water has no adverse impact on the environment and has an extremelylow impurity content, it can also be expected to have the effect ofcleaning the front surface of the substrate P and the surface of theoptical element provided on the front end surface of the projectionoptical system PL. Furthermore, the exposure apparatus may be providedwith an ultrapure water manufacturing apparatus if the purity of thepure water supplied from the plant and the like is low.

Further, the refractive index n of pure water (or water) for theexposure light EL that has a wavelength of approximately 193 nm is saidto be substantially 1.44; therefore, the use of ArF excimer laser light(193 nm wavelength) as the light source of the exposure light EL wouldshorten the wavelength on the substrate P to 1/n, i.e., approximately134 nm, and thereby a high resolution would be obtained. Furthermore,because the depth of focus will increase approximately n times, i.e.,approximately 1.44 times, that of in air, the numerical aperture of theprojection optical system PL can be further increased if it ispreferable to ensure a depth of focus approximately the same as thatwhen used in air, and the resolution is also improved from thisstandpoint.

Furthermore, the numerical aperture NA of the projection optical systemmay become 0.9 to 1.3 if the liquid immersion method as discussed aboveis used. If the numerical aperture NA of such a projection opticalsystem increases, then random polarized light conventionally used as theexposure light will degrade imaging performance due to the polarizationeffect, and it is therefore preferable to use polarized illumination. Inthat case, it is better to illuminate with linearly polarized lightaligned in the longitudinal direction of the line pattern of theline-and-space pattern of the mask (the reticle), and to emit a largeamount of diffracted light of the S polarized light component (the TEpolarized light component), i.e., the polarized light directioncomponent aligned in the longitudinal direction of the line pattern,from the pattern of the mask (the reticle). If a space between theprojection optical system PL and the resist deposited on the frontsurface of the substrate P is filled with a liquid, then thetransmittance through the resist surface increases for the diffractedlight of the S polarized light component (the TE polarized lightcomponent), which contributes to the improvement of the contrast,compared with the case in which the space between the projection opticalsystem PL and the resist deposited on the front surface of the substrateP is filled with air (a gas), and a high imaging performance canconsequently be obtained even if the numerical aperture NA of theprojection optical system exceeds 1.0. In addition, it is furthereffective to appropriately combine a phase shift mask and the obliqueincidence illumination method (particularly the dipole illuminationmethod) aligned in the longitudinal direction of the line pattern, asdisclosed in Japanese Published Patent Application No. H06-188169.

In addition, if the substrate P is exposed with a fine line-and-spacepattern (e.g., a line-and-space of approximately 25 to 50 nm) by using,for example, an ArF excimer laser as the exposure light and using aprojection optical system PL that has a reduction magnification ofapproximately ¼, then the structure of the mask M (e.g., the fineness ofthe pattern and the thickness of the chrome) may cause the mask M to actas a polarizing plate due to the wave guide effect, and a larger amountof diffracted light of the S polarized light component (the TE polarizedlight component) compared with the diffracted light of the P polarizedlight component (the TM polarized light component), which decreasescontrast, is emitted from the mask M, and it is therefore preferable touse the linear polarized light illumination discussed above; however,even if the mask M is illuminated with random polarized light, a highresolution performance can be obtained even if the numerical aperture NAof the projection optical system PL is as large as 0.9 to 1.3. Inaddition, if exposing a substrate P with an ultrafine line-and-spacepattern of a mask M, then there is also a possibility that the Ppolarized light component (the TM polarized light component) will becomegreater than the S polarized light component (the TE polarized lightcomponent) due to the wire grid effect; however, because a greaterquantity of diffracted light of the S polarized light component (the TEpolarized light component) than the diffracted light of the P polarizedlight component (the TM polarized light component) is emitted from themask M if the substrate P is exposed with a line-and-space patternlarger than 25 nm using, for example, an ArF excimer laser as theexposure light and a projection optical system PL that has a reductionmagnification of approximately ¼, a high imaging performance can beobtained even if the numerical aperture NA of the projection opticalsystem PL is as large as 0.9 to 1.3.

Furthermore, instead of just linear polarized light illumination (Spolarized light illumination) aligned in the longitudinal direction ofthe line pattern of the mask (the reticle), it is also effective tocombine the oblique incidence illumination method with the polarizedlight illumination method that linearly polarizes light in a directiontangential (circumferential) to a circle with the optical axis at thecenter, as disclosed in Japanese Published Patent Application No.H06-53120. In particular, if the mask (reticle) pattern includes linepatterns extending in a plurality of differing directions instead ofjust a line pattern extending in a prescribed single direction, then, bycombining the use of the zonal illumination method with the polarizedlight illumination method that linearly polarizes light in a directiontangential to a circle that has the optical axis at its center, assimilarly disclosed in Japanese Published Patent Application No.H06-53120, it is possible to achieve high imaging performance even ifthe numerical aperture NA of the projection optical system is large.

In the present embodiment, the optical element 2 is affixed to the frontend of the projection optical system PL and the relevant lens can adjustthe optical characteristics of the projection optical system PL, e.g.,aberrations (spherical aberration, coma aberration, and the like).Furthermore, the optical element affixed to the front end of theprojection optical system PL may also be an optical plate used to adjustthe optical characteristics of the projection optical system PL.Alternatively, it may be a plane parallel plate that is capable oftransmitting the exposure light EL therethrough.

Furthermore, if high pressure is generated by the flow of the liquid LQbetween the substrate P and the optical element at the front end of theprojection optical system PL, then instead of making the optical elementreplaceable, it may be firmly fixed so that it does not move by thatpressure.

In addition, the exposure apparatus which uses the liquid immersionmethod discussed above has a constitution wherein the substrate P isexposed after filling the space of the optical path on the lightemerging side of the terminal optical element 2 of the projectionoptical system PL with the liquid (pure water), but the space of theoptical path on the light incident side of the terminal optical element2 of the projection optical system PL may also be filled with the liquid(pure water), as disclosed in PCT International PublicationWO2004/019128.

Furthermore, the present embodiment is constituted so that a spacebetween the projection optical system PL and the front surface of thesubstrate P is filled with the liquid LQ, but it may be constituted sothat the space is filled with the liquid in a state wherein, forexample, a cover glass having a plane parallel plate is affixed to thefront surface of the substrate P.

Furthermore, although the liquid LQ in the present embodiment is water,it may be a liquid other than water; for example, if the light source ofthe exposure light EL is an F₂ laser, then this F₂ laser light will notpass through water, so it would be acceptable to use as the liquid LQ afluorine based fluid, such as perfluorinated polyether (PFPE) orfluorine based oil, that is capable of transmitting F₂ laser light. Inthis case, the portions that make contact with the liquid LQ are treatedin order to make them lyophilic by forming a thin film with a substancethat has a molecular structure that contains fluorine and that has a lowpolarity. In addition, it is also possible to use as the liquid LQ one(e.g., cedar oil) that is transparent to the exposure light EL, has thehighest possible refractive index, and is stable with respect to theprojection optical system PL and the photoresist deposited on the frontsurface of the substrate P. In this case as well, the surface treatmentis performed in accordance with the polarity of the liquid LQ used. Inaddition, a liquid can also be used that has a refractive index that ishigher than that of the terminal optical element 2 of the projectionoptical system PL with respect to the exposure light EL.

Furthermore, the substrate P in each of the abovementioned embodimentsis not limited to a semiconductor wafer for manufacturing semiconductordevices, and may be a glass substrate for a display device, a ceramicwafer for a thin film magnetic head, the original plate of a mask orreticle (synthetic silica glass, silicon wafer) used by an exposureapparatus, or the like.

In addition, the exposure apparatus EX may be a step-and-scan systemscanning type exposure apparatus (scanning stepper) that performsexposure by scanning the pattern of the mask M by synchronously movingthe mask M and the substrate P, as well as a step-and-repeat systemprojection exposure apparatus (stepper) that exposes the substrate Pwith the full pattern of the mask M, with the mask M and the substrate Pin a stationary state, and sequentially step-moves the substrate P. Inaddition, the present invention can also be adapted to a step-and-stitchsystem exposure apparatus that transfers at least two patterns onto thesubstrate P so that the patterns are partially superimposed on eachother.

In addition, in the embodiments discussed above, an exposure apparatusis adopted that a space between the projection optical system PL and thesubstrate P is locally filled with a liquid, but the present inventioncan also be adapted to a liquid immersion exposure apparatus wherein theentire front surface of the substrate to be exposed is covered with theliquid. The structure and the exposure operation of the immersionexposure apparatus wherein the entire front surface of the substrate tobe exposed is covered with the liquid are disclosed in detail in, forexample, Japanese Published Unexamined Patent Application No. H6-124873,Japanese Published Unexamined Patent Application No. H10-303114 and U.S.Pat. No. 5,825,043, the disclosures of which are each herebyincorporated by reference in its entirety to the extent permitted by thenational laws and regulations of the designated states (or electedstates) designated by the present international patent application.

The type of exposure apparatus EX is not limited to semiconductor devicefabrication exposure apparatuses that expose the substrate P with thepattern of a semiconductor device, but the present invention can also bewidely adapted to exposure apparatuses for manufacturing liquid crystaldevices or displays, exposure apparatuses for manufacturing thin filmmagnetic heads, imaging devices (CCDs), or reticles and masks, and thelike.

If a linear motor is used in the substrate stage PST or the mask stageMST (refer to U.S. Pat. No. 5,623,853 and U.S. Pat. No. 5,528,118), theneither an air levitation type that uses an air bearing, or a magneticlevitation type that uses Lorentz's force or reactance force may beused. In addition, each of the stages PST, MST may be a type that movesalong a guide or may be a guideless type.

For the drive mechanism of each of the stages PST, MST, a planar motormay be used that opposes a magnet unit, wherein magnets are arranged twodimensionally, to an armature unit, wherein coils are arranged twodimensionally, and drives each of the stages PST, MST by electromagneticforce. In this case, any one among the magnet unit and the armature unitis connected to the stages PST, MST and the other one should be providedon the moving surface side of the stages PST, MST.

The reaction force generated by the movement of the substrate stage PSTmay be mechanically discharged to the floor (ground) by using a framemember so that it is not transmitted to the projection optical systemPL, as recited in Japanese Published Patent Application No. H08-166475(U.S. Pat. No. 5,528,118).

The reaction force generated by the movement of the mask stage MST maybe mechanically discharged to the floor (ground) by using a frame memberso that it is not transmitted to the projection optical system PL, asrecited in Japanese Published Patent Application No. H08-330224 (U.S.Pat. No. 5,874,820).

The exposure apparatus EX of the embodiments in the present applicationis manufactured by assembling various subsystems, including eachconstituent element recited in the claims of the present application, sothat prescribed mechanical, electrical, and optical accuracies aremaintained. To ensure these various accuracies, adjustments areperformed before and after this assembly, including an adjustment toachieve optical accuracy for the various optical systems, an adjustmentto achieve mechanical accuracy for the various mechanical systems, andan adjustment to achieve electrical accuracy for the various electricalsystems. The process of assembling the exposure apparatus from thevarious subsystems includes the mutual mechanical connection of thevarious subsystems, the wiring and connection of electrical circuits,the piping and connection of the atmospheric pressure circuit, and thelike. Naturally, before the process of assembling the exposure apparatusfrom these various subsystems, there are also the processes ofassembling each individual subsystem. When the process of assembling theexposure apparatus from the various subsystems is finished, acomprehensive adjustment is performed to ensure the various accuraciesof the exposure apparatus as a whole. Furthermore, it is preferable tomanufacture the exposure apparatus in a clean room wherein thetemperature, the cleanliness level, and the like are controlled.

As shown in FIG. 20, a micro-device, such as a semiconductor device, ismanufactured by: a step 201 that designs the functions and performanceof the micro-device; a step 202 that fabricates a mask (reticle) basedon this design step; a step 203 that fabricates a substrate, which isthe base material of the device; an exposure processing step 204 whereinthe exposure apparatus EX of the embodiments discussed above exposes thesubstrate with a pattern of the mask; a device assembling step 205(including a dicing process, a bonding process, and a packagingprocess); an inspecting step 206; and the like.

INDUSTRIAL APPLICABILITY

The detection apparatus is used to detect the presence of liquid on anobject disposed lower than the front end of a projection optical system,the state of the immersion area, or the shape or contact angle of theliquid, and it is therefore possible to take optimal measures, based onthose detection results, in order to maintain high exposure andmeasurement accuracies. For example, if the immersion area is not formedat the desired position, then an appropriate measure should be taken,based on the detection results of the detection apparatus, to disposethe liquid at the desired position. In addition, if liquid flows out andadheres to a position outside of the desired position, then appropriatemeasures should be taken based on the detection results of the detectionapparatus, e.g., stopping the supply of the liquid, removing the liquid,and the like. Thereby, a device that has the desired performance can bemanufactured.

1. An exposure apparatus comprising: a substrate stage on which asubstrate is held, the substrate stage being movable while holding thesubstrate; a projection optical system through which an image of apattern is projected onto the substrate held by the substrate stage whenthe substrate is disposed adjacent to a final optical element of theprojection optical system, a liquid being provided in a space betweenthe final optical element and the substrate so as to contact the finaloptical element and the substrate; and a detection apparatus thatdetects whether the liquid is present on an object that is disposedlower than the final optical element of the projection optical system ata time when the image of the pattern is projected by the projectionoptical system onto the substrate, the object being at least one of thesubstrate stage, the substrate and a member that moves with thesubstrate stage.
 2. An exposure apparatus according to claim 1, wherein:the detection apparatus has an emitting portion that emits detectionlight and a light receiving portion.
 3. An exposure apparatus accordingto claim 2, wherein: the detection light is emitted from the emittingportion to a plurality of positions, and at least one of a size and ashape of the liquid on the object is obtained based on a light receivingresult of the light receiving portion.
 4. An exposure apparatusaccording to claim 2, wherein: the detection apparatus performs thedetection while the detection light and the object are relatively moved.5. An exposure apparatus according to claim 4, wherein: the object ismovable with respect to the projection optical system.
 6. An exposureapparatus according to claim 2, further comprising: a bending portionspaced from the liquid and that bends an optical path of the detectionlight.
 7. An exposure apparatus according to claim 2, wherein: thedetection light travels through the space between the final opticalelement and the substrate substantially parallel to a surface of thesubstrate.
 8. An exposure apparatus according to claim 7, wherein:whether the liquid is present in an optical path of the detection lightis determined based on a light receiving result of the light receivingportion.
 9. An exposure apparatus according to claim 7, wherein: thedetection light passes through an area away from the surface of theobject by 5.5 mm or less than 5.5 mm.
 10. An exposure apparatusaccording to claim 2, wherein: a position of the liquid on the object isobtained based on a light receiving result of the light receivingportion.
 11. An exposure apparatus according to claim 2, wherein: theemitting portion emits the detection light to the space between thefinal optical element and the substrate.
 12. An exposure apparatusaccording to claim 2, wherein: the emitting portion emits the detectionlight to a surface of the object.
 13. An exposure apparatus according toclaim 12, wherein: the light receiving portion receives light from thesurface of the object, and the liquid on the surface of the object canbe detected based on the light receiving result.
 14. An exposureapparatus according to claim 12, wherein: the surface of the objectincludes a recessed portion formed on the object.
 15. An exposureapparatus according to claim 14, wherein: the object is the substratestage, and the recessed portion is provided in the substrate stage, anda substrate holder that holds the substrate is disposed in the recessedportion, and the detection apparatus also detects whether liquid ispresent on the substrate holder at a time when the substrate is not heldon the substrate holder.
 16. An exposure apparatus according to claim15, wherein: the emission of the detection light to the substrate holderis performed before loading the substrate on the substrate holder. 17.An exposure apparatus according claim 2, wherein: the detection light isinfrared light.
 18. An exposure apparatus according to claim 2, wherein:the detection light includes a sheet light flux.
 19. An exposureapparatus according to claim 1, further comprising: a liquid supplysystem having a supply port, that supplies the liquid; a liquid recoverysystem having a recovery port, that recovers the liquid; and acontroller that controls an operation of at least one of the liquidsupply system and the liquid recovery system based on a detection resultof the detection apparatus.
 20. An exposure apparatus according to claim19, wherein: the controller stops the supply of the liquid by the liquidsupply system if it is determined that the detection result of thedetection apparatus is abnormal.
 21. An exposure apparatus according toclaim 1, wherein: an exposure operation is controlled based on adetection result of the detection apparatus.
 22. An exposure apparatusaccording to claim 1, wherein: a warning is issued if it is determinedthat a detection result of the detection apparatus is abnormal.
 23. Adevice manufacturing method comprising: exposing the substrate throughthe projection optical system of the exposure apparatus according toclaim 1; and processing the exposed substrate.